Skip to content

PRG-340-3 | CASIO


Personal Menu

PRG-340 Series


My GShock

Get out into the great outdoors with a solar-powered PRO TREK featuring eco-friendly materials that care for the environment. The PRO TREK line of authentic outdoor gear for nature lovers introduces the PRG-340, a timepiece that incorporates environmentally friendly biomass plastics* while delivering the same comfortable fit for your wrist. The case and urethane band are crafted from biomass plastics made with castor oil and the band from biomass plastics made with corn. The duplex LCD lays out separate layers for the compass graphics and the clock functions, enabling a larger compass display for better legibility and easier navigation in a design that is both functional and beautiful. The rotating bezel makes it simple to record compass readings, and the Tough Solar charging system keeps the advanced functionality on the go. Get out and explore with a gentler footprint! * Biomass plastics are polymers produced using chemical or biological synthesis of materials sourced from plant matter or other renewable organic substances and are widely thought to help reduce environmental impact and promote the shift to a circular economy.

Digital compass display
Altimeter display
Barometer / Thermometer display


Biomass plastics used for most parts: A digital model with a duplex LCD

We’ve added a duplex LCD to our digital model with direct function buttons for one-push measurements. The rotating bezel, case, case back, and urethane band are made with plant-derived, renewable biomass plastics. Introducing this PRO TREK and celebrating its trailblazing progress in every direction: easy to use, easy to read, easy on the environment.



Digital compass now even more
readable with the duplex LCD

The dual-layer LCD allows compass graphics to be shown on the top layer, while the bottom layer offers a large display of the time and various measurements. We’ve also made the LCD slimmer to minimize bulk, even with the dual-layer construction.


Earth-friendly craftsmanship with
biomass plastics

The case, case back, and soft urethane band are all made with the Earth-friendly green material known as biomass plastics. Using renewable organic resources such as castor oil plants and corn helps reduce the ecological footprint. Eco-consciousness rendered in physical form, a fitting material for a real outdoor tool.
*Biomass plastics are not used in the metal band of the PRG-340T.



Direct function buttons for increased

Measure direction, air pressure and temperature, and altitude, each one available directly from a single button. The oversized buttons feature a nonslip finish for effortless use even when wearing gloves. In addition, improved sensor placement makes the side of the case even slimmer. The buttons are easier to press now, too.


Rotating bezel and movable lug construction

The bezel incorporates a rotating mechanism, allowing it to be used for simple orientation memory. The movable lug structure enables the watch case and band to be laid flat — handy when working with paper maps, checking where you are and where you’re going.

Triple Sensor (digital compass, barometer/altimeter, and thermometer) senses natural changes

Tough Solar powered for converting light to energy

Super Illuminator (high-brightness full-auto LED backlight) for main-taining watch readability in the dark
*Image shows the PRG-340-1.

Developer interview video


  • 10-bar water resistance
  • Low-temperature resistance (-10℃)
  • Tough Solar (solar powered)
  • World time (48 cities)
  • Digital compass
  • Barometer
  • Altimeter
  • Thermometer
  • Sunrise, sunset time display
  • 1/10-second stopwatch (measuring capacity: 1,000 hours)
  • Countdown timer
  • 5 daily alarms
  • Full-auto LED backlight (Super Illuminator)

*The color tone of the listed products may differ from the actual product in some cases.

Select a location