Tourna Cross String Savers : Minimize your string friction and extend the life of your strings with Tourna Cross, an easy to install system made of durable plastic that is great for both natural gut and synthetic strings. Increases sweetspot. Increased roughness for better control and ball spin. Will not negatively impact playability. Used by pros on tour. 35 durable plastic crosses on each strip. Easy to install with the Tourna Cross tool. Tourna Cross tool included. Purchase includes 1 Tourna Cross tool and 5 strips.