thickness : 2.1 mm

hardness : hard 40

review : 

The rubber adopts the new internal energy technology of NEW-RELEASE PRO, which makes the performance of the sponge maximally, the rubber can be in a storing energy accumulation stage for a long time and still achieve good effect without oil or glue filing. 

The super effectiveness and rotation of rubber, coupled with the support of the new internal energy sponge the feling of playing ball, explosive power, perfectly combine rotation and strength.