Keen is the narrowest string created by String Project. The cobalt-blue exterior hides a very narrow section, 1.18 mms and 1.13 mms, but just as strong as any other. The composition is a concentrated technological blend, a mixture of 5 different materials that make it incredibly solid and reactive after a snapback. With its sensitive and powerful qualities, Keen increases the ability for spinning during the game, creating a natural connection with the ball and multiplied effect of power and rotation.
Its narrow calibre gives the right feel to tame thrust and to perceive the ball at its best when on the head of the racket, with a notable natural control over the direction of the shot. Slender but enduring, Keen yields very well on control-based rackets and manages to enhance and simplify the player’s performance when in use. Soft and elastic it also manages to protect the arm on impact.