Tourna Big Hitter Black 7 Ultimate Spin String, Black7 Reel 7 sided polyester that really bites into the ball for ultimate spin and control Awarded #1 in spin - out of all strings EVER tested per USRSA playtests. Advanced co-poly construction for a soft feel that is easy on the arm Made in Germany with the most advanced string production technology in the world 660-Foot reel of string, enough for about 16 racquets. Available in 15L, 16g, and 17g.