These models were released in 1996, designed and specifically made for the surfing market. These models were the very first G-Shock watches to have a countdown timer. The countdown timers on these models were designed to count down for surfing competitions, so a surfer can keep track of the progress while competing on the water. Many of these models came equipped with a pair of strap adapters and a single one-piece resin or nylon band. These styles of band are also known as "crossband" in the Japanese domestic market. Resin bands for these models had open gaps or slits through the band. Casio refers to them as drainage slits; the idea is that water will drain out with no problems while in action when surfing. Most of these series models had a translucent band. These models were branded as X-Treme for the Japanese domestic market.