Commonly used sliders have two types: flange type, and square type. The former is a little lower,but more wider, and the mounting hole is a threaded hole, while the latter is a little higher and narrower, and the mounting hole is a blind thread hole. Both have short type, standard type and elongated type, the main difference is that the length of the slider body is different, of course, the hole spacing of the mounting hole may also be different, most short type slider only has 2 mounting holes.