Check valve 12×1.25 for Showa shock absorbers.
It separates the compression from the rebound. Normally the oil in the compression phase flows through the rebound adjuster, the check valve obligates the oil in the compression phase to pass through the shims. It does NOT affect the rebound.
Installing the check valve there’s more range of use for specialties that require a stiffer shock absorber. For Motocross and Enduro it’s only recommended for professional or very fast riders with aggressive riding.
Recommended for Supermotard and Supercross.
N.B. The check valve is delivered without hole in order to be drilled based on own needs, the more the hole is tight, the more the shock is stiff.
(See recommended drilling).