The Tecnifibre X-R1 1.30 tennis string has PHP monocore for better feel & greater durability, multifilaments & PU inside with 400% elasticity for ultimate comfort & dynamic performance, & SPL (Silicum Pyrogéné Lubritec) anti-abrasion coating, which further increases its durability. The string is supplied in a 40ft (12m) set, which is enough to re-string one racket.