Super tension back soft rubber.
When its mark V and standard 10 speed 11 +.
If spin 10 criteria and its mark V 12.
If the control was standard 10 and its mark V 8.
Rubber made of Yasaka STS (spin tension system) that their own production methods.
It is selling a powerful spin speed and hitting sound is obtained without using glue-bouncing,.
In addition to fast, spin is often take rubber.