The tecnifibre x r1 125 tennis string is the most accessible premium range string by tecnifibre it features a php monocore fiber providing great feel and durability 1 125 multifilaments which increase its power and pu 400 inside for greater comfort the strings durability is further increased by the anti abrasion spl coating the x r1 125 is supplied in a 12m 40ft set which is enough for one re stringing it has a gauge of 125mm