Automatic spring tensioned jaws, which make it simple to position the puller with one hand. Can be used in either two-leg, or three-leg configuration. This gear puller can be changed to operate with 2 or 3 jaws.Internal or external pulling action 75 - 180mm. Simply unscrew the knurled screw cap to release spring and jaw cover, unhook the jaws and replace as necessary. Replace cover plate and tighten spring with knurled screw.