With playability so close to natural gut that you'll want to check the packet for hoof prints, 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. More playable and spin friendly than NRG2 SPL 16 but slightly less durable.