ITF Approved, Pressurised Balls Packed in a Petcan of 3 Balls.
The Tretorn Serie+ Tennis Balls feature extra durability on all court surfaces provided by a special mix of wool, cotton and synthetic fibres. Serie+ balls are the first tennis balls in the world with a unique TRI-TEC sealing membrane, which is used to retain air and keep balls pressure significantly longer than any conventional pressurised ball.
Official Ball of ATP World Tour and ATP Challenger Tour.