Solinco-X-Natural Tennis String Black-() Players who want a multifilament string with more controllable power, a crisp feel and improved access to spin will enjoy Solinco X Natural string. The string takes high performance modulus fibers and binds them with a proprietary thermoplastic polyurethane (TPU) resin... Size - (See Description) | Color - (See Description) Authorized Solinco Dealer. All racquets are strung and ready for the courts! SEE SELLER DETAILS FOR RETURN POLICY.