Each watch in the Pro Trek Navy Blue Series has a unique type of band.
The Pro Trek Navy Blue Series includes three watches from the safari-inspired PRG-600, PRG-650, and PRW-6600 lines. All three models have Tough Solar power along with the Triple Sensor Version 3 (with altimeter-barometer, compass, and thermometer) and 100-meter water resistance. Other features include the “Smart Access” electronic crown, a barometric pressure alarm, low-temperature resistance (–10°C/14°F), and full auto dual LED lights. Each model also has its own unique features as outlined below.
The PRG-600YB-2JF (list price ¥48,000 JPY), PRG-650YL-2JF (¥48,000), and PRW-6600Y-2JF (¥52,000) are March 2019 releases in Japan. The PRG-600YB-2 and PRG-650YL-2 are also being released in other Asian markets and Europe. Casio America announced the PRG600YB-2 (list price $320 USD) and PRW6600Y-2 ($350 USD) as the Pro Trek Midnight Navy Series for an April 2019 release.
The Pro Trek PRG-600YB-2 has a blue ion-plated stainless steel bezel, a blue dial, and a blue cloth band.
The Pro Trek PRG-650YL-2 has a gray ion-plated stainless steel bezel, a blue dial , and a black leather band. This PRG-650 model also has the Neon Illuminator black light LED for enhanced viewing of the hands and markers in the dark.
The Pro Trek PRW-6600Y-2 has a gray ion-played stainless steel bezel, a blue dial, and a dark blue Duro Soft silicone band. This model has Multi-Band 6 for automatic radio wave timekeeping in addition to Tough Solar. It also has a Neon Illuminator LED light.