Wilwood Residue Check Valves are Designed to hold pressure in the line from the master cylinder towards the wheel to remove air in the line that can develop from a high point in the line, or the wheel cylinder or disc brake caliper is higher than the master cylinder.                                                                                                                                                                                                                                                                               -260-02     (disc)       2 lb. valve   (Blue
260-10     (drum)   10 lb. valve   (Red)

Both valves have 1/8 npt female