The Babolat RPM Blast 17G + VS 16G Hybrid is the hot, new string that is taking over the Pro tour. This Babolat string will increase spin, give you more ball speed out of the frame and offer a unique feel during ball impact. The octagonal section gives the player better grip for more spin. The high-density co-polyester material allows for a great combination of power and unique ball feel. The BT7 technology improves on the strings construction. The original construction was 13 bands. Babolat improved the best string ever with new construction based on 7 stronger bands. The bigger surface for contact of bands leads to better cohesion. Better cohesion leads to better durability.