Casio’s PRO TREK PRW-51LD adds a phosphorescent, fully lumed dial to the PRW-51 design, so its analog face can glow in the dark without pressing a light button. That is useful when a hiker’s hands are occupied. It complements—not replaces—the watch’s separate double-LED light for illuminating the face and LCD.
What the PRW-51LD’s hands-free upgrade does
The practical change is the dial’s phosphorescent treatment: after exposure to light, it can glow in low-light conditions without the wearer activating a control. Casio’s Japan product listing identifies the PRW-51LD-1JF and lists Neobrite alongside a double LED light. These are distinct features: the dial glow is passive, while the LEDs provide active illumination when switched on. The distinction matters on a trail if both hands are occupied, but Casio’s product listing does not establish how long or brightly the dial glows under particular conditions. Casio’s PRW-51LD-1JF specifications describe the listed variant.
Outdoor features and specifications
Casio lists an analog-digital PRO TREK configuration with outdoor sensors, solar charging and radio time calibration. The following dimensions, weight, price and release timing refer specifically to the Japanese PRW-51LD-1JF listing; they should not be read as international availability or street-price information.
| Feature | Casio-listed specification |
|---|---|
| Japan listing | PRW-51LD-1JF; listed release: October 2026; suggested retail price: ¥61,600 including tax |
| Size and weight | 51 × 47.4 × 14.5 mm; 55 g |
| Case and band | Resin and stainless-steel case/bezel; bio-based resin soft urethane band |
| Navigation and weather sensors | Digital compass with 16-point direction display, altimeter, barometer and thermometer |
| Altimeter range | −700 to 10,000 m |
| Barometer range | 260 to 1,100 hPa |
| Temperature range | −10°C to 60°C |
| Power and timekeeping | Tough Solar charging and Multiband 6 radio time calibration |
| Lighting | Double LED lighting for face and LCD; selectable 1.5- or 3-second illumination with afterglow |
| Resistance | 100-meter water resistance; low-temperature resistance to −10°C |
Sensor ranges describe what the watch can display, not professional-grade accuracy. For Casio’s qualifications on measurement and compass use, see the Operation Guide 3499.
#1 Best Overall
- Solar-powered sport watch with stainless steel rotating bezel featuring digital dial with day/date display and backlight , Thermometer Display range - -10 to 60 C , Display unit - 0.1 C
- Features triple sensor, atomic timekeeping, low-temperature resistance, digital compass with bearing memory, altimeter, barometer, thermometer, sunrise and sunset data, world time, four daily alarms with snooze, 1/10-second stopwatch, countdown timer, 12/24-hour formats, and power-saving function and 56 mm resin case with mineral dial window
- Titanium band with fold-over-push-button-clasp-with-safety closure
- Water resistant to 200 m (660 ft)
- Altimeter Measuring range: -700 to 10,000 m
How it compares with the PRW-61LD and Rangeman
PRW-61LD: another phosphorescent PRO TREK
The PRW-61LD is a related option with a phosphorescent dial treatment. Casio’s Middle East and Africa product page says its Neo-Brite treatment is integrated into the solar dial and glows in low light. The PRW-51 is described as having Arabic numeral hour markers and a more casual field-watch look, compared with the PRW-61LD’s more tactical tool-watch styling. The available specifications do not establish that the two models share dimensions, sensors or pricing, so compare their individual regional product listings rather than assuming feature parity. Casio’s PRW-61LD-5 page covers that market’s model listing.
GW-9400 Rangeman: a different format
The G-SHOCK Rangeman GW-9400 is a rugged digital alternative, not another version of the PRW-51LD’s luminous-dial upgrade. Casio lists shock resistance, 20-bar water resistance, solar power, barometric pressure and altitude readings, and a compass. Consider it if a digital display and its listed resistance features matter more than the PRO TREK’s analog-digital presentation. See Casio’s European GW-9400-1 product page for that regional listing.
Rank #2
- PRO TREK
- Item shapeRound
- Power source typeSolar Powered
- Clasp typeBuckle
What the watch’s sensors can—and cannot—tell you
Casio cautions that the watch’s measurement functions are not intended for professional or industrial precision and that their values should be treated as reasonable representations. Its Operation Guide 3499 also advises hikers and climbers to carry a second compass when getting lost could be dangerous. The compass, altimeter, barometer and thermometer can be useful references, but the guide’s warnings make clear they are not substitutes for suitable navigation instruments or professional measurements.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Release and price depend on the market
Casio’s Japan page lists the PRW-51LD-1JF as released in October 2026 with a suggested retail price of ¥61,600 including tax. Those are Japan-specific listing details; they do not establish launch timing, local pricing or seller availability in another country. Check Casio’s page for the market where you plan to buy and confirm the exact regional SKU.
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Quick Recap
Best Value
- Dial Color: Silver Strap Color: Black
- Strap Material: Resin Clasp Type: Buckle
- Case Material: Resin Water Resistant
Rank #4
- RUGGED DESIGN WITH FLAME-RESISTANT CORDURA BAND: Gear up with a flame-retardant CORDURA re/cor band built for campfires. The stainless steel and bio-based resin case provides a rugged build, offering maximum durability for outdoor enthusiasts.
- MULTI-BAND 6 RADIO-CONTROLLED TIMEKEEPING: Stay flawlessly accurate with Multi-Band 6 atomic time calibration. Automatically sync with six global stations across the US, Europe, and Asia for precise, hands-free timekeeping wherever your travels take you.
- TRIPLE SENSOR TECHNOLOGY FOR OUTDOOR READINGS: Read the elements with an altimeter, barometer, thermometer, and compass. Track elevations to 10,000m and anticipate weather shifts, giving you total confidence on hiking and camping adventures.
- SOLAR POWERED WITH LONG BATTERY LIFE: Harness the sun with Tough Solar technology. Get up to 6 months of power on a full charge, or 25 months in power-saving mode. Enjoy total reliability and peace of mind on extended outdoor adventures.
- SUPER ILLUMINATOR LED & WORLD TIME FUNCTION: Read clearly in the dark with a powerful double LED Super Illuminator. Track time effortlessly across 29 zones and 48 cities, delivering ultimate convenience for travelers and outdoor explorers.
Rank #3
- Our rubber strap is made of high-quality rubber, The strap is moderately soft and hard,which is sweat resistant, waterproof, and durable
- The watch buckle is made of 316L stainless steel buckle, which is sturdy and durable
- This strap is only suitable for the PRW3500 PRG260 PRG550 series
- Packaging includes: This set includes 1 strap and 2 tools
- If you are unsure if your watch is compatible, please contact us and we will reply to you within 24 hours
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
