Allstar Brake Proportioning Valve has a proportioning valve that allows adjustment of front-to-rear brake bias with a simple twist of the knob. The valve provides up to 57 percent reduction and has fitting ports that are 1/8 npt. The valve also includes two fittings to adapt to 3/16 inches brake line. The dimensions are 1 inches long x 1-3/4 inches wide and 3-5/16 inches tall..