Adjustable-width design that either clamps onto front or rear of seat rails or bolts on to seat mount points to fit a wide variety of vehicles Compatible with Kidde Marine and Automotive models 466627N or 466179, H3R Performance Halguard models HG100 or HG250, Amerex Halotron model B385TS, or any 2 – 2.5lbs extinguishers with a supplied cradle with hole spacing of 4-¼, 4-⅝” or 5” center to center.