The Tournament Plus model is a monofilament (consisting of one fiber) polyester string. The pleasurable feeling while playing, its high ball acceleration and its elasticity are due to a second heating process, the Double Heating.   Materials Surface: coating Core: polyester, monofilament Pre-stretching: string   Technologies Double Heating: the Double-Heating process evens out any irregularities and eliminates internal stresses. Pre-stretched: Pre-stretching the string core reduces the loss of tension to a minimum.   Tips for kings Normal string tension for normal and large head sizes, normal and wide string patterns.