The next generation of traction technology is here. Three degrees of traction, ten points of contact, engineered to deliver incredible control and unmatched stability Fit & Design: Featuring our exclusive center stinger post Tour Flex Pro is the perfect combination of traction, comfort and performance - designed specifically to meet the needs of the best players in the world The most advanced insert system on the market Cross-compatible with Tour Lock(TM) and Slim-LOK(R) Additional Details: Insert Systems refers to the type of receptacle found on the bottom of your shoe. The Insert System determines the type of spike that will fit your shoe. Different manufacturers use different types of receptacles, so it's important to be able to match the right spike to the right Insert System