The most durable version of NXT in the game, NXT Duramax features Abrasion Shields to protect PU-bonded fibers in core and layer extra resistance to string breakage. Perfect for players who prefer the classic, comfortable feel of NXT but struggle with breaking strings, NXT Duramax offers a solution without compromising the impressive power, spin and comfort synonymous with NXT string. This 15 gauge string is slightly thicker than the 16 gauge, making it a more durable option.