Volkl-Psycho Hybrid 17G Tennis String Black and Silver-(847586014553) A hybrid string with the comfort of gut-like string and the enhanced control of a polymer, the Volkl Psycho Hybrid 17G Tennis String Black and Silver is a great string for players who want the full package. Go PSYCHO on the court with this powerful string that packs a mean punch... Dual Comfort And Control | Enhanced Shock Absorption | Excellent Durability Size - (See Description) | Color - (Black) Authorized Volkl Dealer. All racquets are strung and ready for the courts! SEE SELLER DETAILS FOR RETURN POLICY.