Tennis strings are available in store only. Please call our tennis department during regular store hours if you have any questions - (425) 869- 7669 The Tecnifibre NRG2 is a premium quality multifilament synthetic string. The durability benefits of the Silicon Pyrogene Lubritec additive are complemented with lasting feel and comfort providing continued performance for the discerning player. Excellent touch and feel. Tecnifibre NRG2 16 Tennis String | Natural | Christy Sports