For tennis athletes looking for the delicate balance between flexibility, stability and lightweight, the new FW18 VIPER ULTRA is an attractive choice. The exclusive K-PU net supports fast, twitch-like movement, and upward stability during players’ multi-directional bursts of motion, and long lasting durability (RFC® together with LL40® outsole high-quality rubber), serve after serve after serve. The VIPER ULTRA outsole ensures stability (FAS®), cushioning (Enerturn®) and the correct foot positioning.