The Tecnifibre X-R3 1.35 tennis string provides a firm, crisp feel, enhanced comfort & power. The string has a multifilament technology which composes of three monofilament cores, PU 400 inside & Elastyl fibres. The monofilament cores have proven to provide a firm feel, increased control & enhanced durability. The Elastyl fibres enhance power, while the Polyurethane 400 inside improves comfort by minimizing shock & vibration. The Tecnifibre X-R3 has a 1.35mm gauge & is available in a 12.2m (40ft.) set.