Introducing the new Luxilon Smart , a technologically advanced co-polyester string with an impressive combination of control, durability and feel. As with the M2 and Element series, Luxilon has developed this string with variable flexibility to ensure optimal performance at different swing speeds. With faster swings, the Smart becomes firmer, giving the attacking player the control needed to increase both power and spin. For slower or more compact shots, the Smart is designed to be softer for improved touch, power and feel. The result is an extremely versatile co-polyester string that should work very well for a wide range of players.