The residual valve with blue anodized finish is 2 psi pressure valve. It is aluminum alloy made type. The replacement numbers are Wilwood# 260-3278, RPV2, RPV2W. The thread size of the female brass fitting is 3/8-24". The residual pressure valve is used in fron disc, rear disc brake system or rear drum brakes, which fits for racing cars, drifting, ect.
