R31 House – Aluminum Upper Arm Adapters 34.5mm – #R31S063

This is the aluminum upper arm adapter 34.5mm from Shibata GRK R31 House.

D-cut type aluminum upper shaft for GRK4/GRK5 upper arm.

This hard anodized product is made of aluminum.

Significant weight reduction compared to standard steel upper shaft.

The total shaft length (including the screw part) is used for the GRK5 front upper arm.

Same 34.5mm as the upper shaft.

Applicable upper arm

– GRK4 standard upper arm

– GRK5 standard upper arm

– PM upper arm set R31S301