The Casio PRJ-B001EX is a unique outdoor watch launching in August 2026 that solves a specific problem for hikers: carrying cash without a wallet. Its defining feature is a reversible strap that unzips into a secure coin pouch and includes a carabiner for backpack attachment. Official specs confirm a 51-gram weight, 100-meter water resistance, and Tough Solar charging with up to 18 months of battery life in power-save mode. Priced at approximately $208 USD (¥33,000 JPY), it costs more than the similar PRJ-B001B model but offers unmatched utility for minimalists and travelers who need secure, accessible storage on the trail.
Introduction to the Casio PRJ-B001EX
The Casio PRJ-B001EX represents a shift in how outdoor watches are designed, focusing on utility rather than just adding more sensors. Officially set for release in August 2026, this timepiece is part of Casio’s Pro Trek “Hiker Line,” created specifically for people who spend significant time in nature. Unlike standard digital watches, this model addresses the practical need to carry small essentials like cash and keys without a bulky wallet.
This watch combines rugged durability with smart connectivity, featuring solar charging and Bluetooth synchronization. It is important to distinguish this “EX” model from other versions in the series, as it possesses a unique strap mechanism not found on cheaper alternatives. The following sections detail exactly what makes this watch a standout tool for adventurers.
The Revolutionary Zippered Strap Design
The most critical aspect of the Casio PRJ-B001EX is its strap, which functions as a multi-purpose tool rather than just a band. This design element transforms the watch from a simple timekeeper into a secure storage device for hikers and travelers.
How the Coin Pouch Works
The strap is engineered to unzip and reveal a hidden, reversible compartment that serves as a coin and cash pocket. This feature allows users to store campsite cash, transit tickets, or small bills directly on their wrist, eliminating the need to dig through a backpack for small purchases. The zipper closure ensures that items remain secure even during vigorous activities like climbing or scrambling over rocks.
When not in use as a pouch, the strap maintains the appearance of a thick, durable band made from bio-based resin. The design is intuitive, allowing quick access to funds while keeping them safe from falling out during movement. This functionality is particularly valuable for minimalists who wish to leave their main wallet safely stored in a tent or hotel room.
Backpack Attachment and Protection
Beyond storing cash, the strap includes a detachable carabiner loop that enables versatile mounting options. Users can unclip the watch from their wrist and attach it directly to a backpack strap, belt loop, or gear harness, keeping it accessible without occupying wrist space. This feature also enhances security, allowing travelers to clip the watch inside a bag or jacket to prevent theft.
An additional protective feature is the strap’s ability to fully enclose the watch face when folded. By wrapping the band around the watch head, users can shield the glass and buttons from scratches and impacts when the device is tossed into a gear bag without a case. This dual function of storage and protection makes the strap the central innovation of the Casio PRJ-B001EX.
Official Specifications and Performance
Accurate technical data is essential for buyers, especially given the confusion caused by early leaks regarding this model. The following specifications are verified against official sources from Casio Japan and high-authority technical reviews to ensure correctness.
Verified Technical Data
The Casio PRJ-B001EX is a substantial timepiece designed for readability and durability in outdoor conditions. Its dimensions and weight reflect the robust mechanism required for the zippered strap system.
| Specification | Detail |
|---|---|
| Model Number | PRJ-B001EX |
| Release Date | August 2026 |
| Case Dimensions | 50.3 × 46.0 × 13.6 mm |
| Official Weight | 51 grams |
| Water Resistance | 10 bar (100 meters) |
| Glass/Display | Dual Super Illuminator LED |
| Case Material | Bio-based resin |
| Battery Life (Normal) | Approx. 7 months |
| Battery Life (Power Save) | Approx. 18 months |
| Charging System | Tough Solar |
| Connectivity | Bluetooth (Smartphone Link) |
| Time Accuracy | ±15 seconds per month (no signal) |
Clarifying Weight Discrepancies
There has been significant confusion regarding the weight of this watch, with early leaks suggesting it might weigh 44 grams or even 37 grams. It is crucial to note that the official weight of the PRJ-B001EX is 51 grams. The lighter figures found in some reports refer to the PRJ-B001B model, which uses a simpler urethane band without the zippered pouch mechanism.
The extra weight in the EX model comes from the additional material and hardware required for the reversible pouch and carabiner loop. Buyers should verify the weight and model number when purchasing to ensure they are getting the version with the unique strap features. The case size remains consistent across the series at roughly 50mm in length, providing a large, easy-to-read display for outdoor use.
Key Features for Outdoor Adventures
Beyond its unique strap, the Casio PRJ-B001EX is equipped with a suite of features designed to support long-duration outdoor activities. These capabilities ensure the watch remains functional and reliable in diverse environments.
Tough Solar and Battery Efficiency
The watch utilizes Casio’s Tough Solar charging system, which converts light from any source into energy to power the device. This means users never need to replace batteries, a critical advantage for long expeditions where access to power is impossible. Under normal usage conditions, the watch can operate for approximately 7 months on a full charge without further light exposure.
For extended storage or low-light scenarios, the power-save mode extends battery life up to 18 months by stopping the display when the watch is in the dark. This efficiency ensures that the watch will still be running after being stored in a drawer or a dark backpack for months. Simply exposing the watch to light for a short period will reactivate it and resume normal operation.
Bluetooth Connectivity and Accuracy
Integrated Bluetooth connectivity allows the Casio PRJ-B001EX to pair with a smartphone for automatic time and date adjustment. This “Smartphone Link” feature ensures the watch is always synchronized with atomic time standards, eliminating the need for manual adjustments when traveling across time zones. The watch covers 38 world time cities, making it easy to track time back home or at the next destination.
While the watch maintains an accuracy of ±15 seconds per month on its own, the Bluetooth connection keeps it perfectly precise. This feature is particularly useful for travelers who move frequently between countries and need reliable timekeeping without constant manual intervention. The connection also simplifies the initial setup of the watch’s various functions.
Durability and Visibility
Built for harsh conditions, the watch boasts a 10-bar (100-meter) water resistance rating, making it suitable for swimming, snorkeling, and heavy rain. It is not designed for deep-sea diving but exceeds the requirements for typical water sports and wet hiking trails. The case is constructed from bio-based resin, offering a balance of toughness and environmental consideration.
Visibility in low-light conditions is ensured by the dual Super Illuminator LED lighting system. This feature provides bright, even illumination of the dial, allowing users to read the time clearly inside a tent or on a night hike. Additionally, the rotary guard bezel helps protect the watch face and buttons from accidental impacts against rocks or trees.
Price Analysis and Model Comparison
Understanding the pricing structure is vital because the Casio PRJ-B001EX is priced higher than similar models in the same series. The cost difference is directly tied to the specialized strap design, which is not present on the base models.
Pricing Breakdown
The official list price for the Casio PRJ-B001EX in Japan is ¥33,000, which converts to approximately $208 USD. This price point reflects the added complexity and utility of the reversible zippered strap and the included carabiner hardware. It positions the watch as a premium option within the entry-level Pro Trek lineup.
In comparison, the standard PRJ-B001B model, which lacks the coin pouch strap, is priced significantly lower. The B001B lists for around ¥25,300 (approximately $155 USD) in Japan and about $180 USD in the United States. This price gap of roughly $30 to $50 is the cost of the unique storage functionality found only in the EX model.
Comparison Table: EX vs. B001B
The following table highlights the key differences between the two main models to help buyers decide which version suits their needs.
| Feature | Casio PRJ-B001EX | Casio PRJ-B001B |
|---|---|---|
| Strap Type | Reversible zippered pouch | Soft urethane / Bungee cord |
| Storage | Yes (Coin/Cash pocket) | No |
| Carabiner Loop | Yes | No |
| Weight | 51 grams | 37 grams |
| Price (Approx. USD) | $208 | $155 – $180 |
| Water Resistance | 100 meters | 100 meters |
| Solar Charging | Yes | Yes |
| Bluetooth | Yes | Yes |
Buyers should be cautious of listings that advertise a low price or a light weight (37g) while claiming to be the EX model. These are likely the B001B version. The extra weight and cost of the Casio PRJ-B001EX are the trade-offs for having a secure wallet on your wrist.
Who Should Buy This Watch?
The Casio PRJ-B001EX is a niche product designed for specific types of users who will appreciate its unique form factor. It is not a general-purpose watch for everyone, but it is an ideal tool for certain lifestyles.
Ideal User Profiles
- Hikers and Campers: The ability to carry cash for vending machines or trail fees without a wallet is a major advantage. The carabiner loop allows the watch to be clipped to a pack for easy access.
- Travelers: The secure pouch is excellent for keeping emergency cash or transit tickets safe in crowded areas. The world time and Bluetooth features simplify international travel.
- Minimalists: Individuals who prefer to carry as little as possible will value the integration of storage and timekeeping. It allows for short trips away from camp without needing a bag.
- Outdoor Enthusiasts: The rugged construction, solar charging, and water resistance make it suitable for swimming, climbing, and rough terrain.
Who Might Skip It
Conversely, this watch may not be suitable for those seeking a slim, formal timepiece for office wear. The case is thick at 13.6 mm and wide at 50.3 mm, giving it a bulky, sporty aesthetic that stands out. Additionally, users who do not need the coin pouch feature might find the PRJ-B001B to be a better value due to its lighter weight and lower price.
Some initial feedback from users suggests the all-resin build can feel “plasticky” or “flimsy” compared to metal watches. However, this construction is typical for hiking gear, prioritizing impact resistance and comfort over a premium metal feel. Casio’s reputation for durability suggests the watch will withstand outdoor abuse despite its lightweight materials.
Is It Worth the Cost?
The question of whether the Casio PRJ-B001EX is worth buying depends entirely on the value you place on its unique strap design. If the idea of leaving your wallet behind and carrying cash securely on your wrist appeals to you, then yes, it is absolutely worth the investment.
The innovative reversible pouch adds genuine utility that goes beyond simple timekeeping, transforming the watch into a functional piece of survival gear. When combined with reliable Tough Solar charging, Bluetooth accuracy, and 100-meter water resistance, it offers a compelling package for outdoor adventurers. The price of approximately $208 is justified by the specialized engineering of the strap and the added convenience it provides.
However, if you have no need for a wrist-mounted coin pouch, the extra cost may be hard to justify. In that case, the PRJ-B001B offers the same core performance, solar power, and connectivity in a lighter package for about $50 less. For the target audience of hikers and minimalists, though, the Casio PRJ-B001EX stands out as a creative and practical solution that redefines what a watch strap can do.