TheÃàMissing Link,Ãàin four eye-catching colors, gives bowlers unmatched performance at a low price. We increased the shell strength to S40 and increased the dynamics of the L shaped core, by enlarging it and adding a dense extension arm. This produces a higher RG Differential of 0.045 (in all weights but 10 lb). 900 Global - providing innovative core design with proven shell technology at a great value.