The Diadem Solstice Black 17 1.20 tennis string is aggressively shaped to unleash massive spin. This polyester string features Star Core Technology. a six-pointed geometric cross section that equally distributes contact between the strings. reducing friction while amplifying snapback. Simultaneously. the star shape creates a larger surface area to add more bite on the ball. If you want to achieve maximum spin potential. try the Diadem Solstice Black 17 1.20!