Musclechuck Packages includes the Musclechuck™ assembly, MC25 1/4" Collet Reducer and the HEX532 5/32" x 6" T Handle Key for a quarter turn change of your bits. Once the Musclechuck™ assembly has been installed on the router, it will enable the cutters to be exchanged with extreme ease. The Musclechuck™ assembly gives you easy access when changing cutters and eliminates the cumbersome use of wrenches. Along with its superior grip, it also gives you some extra length when using router plates (approx. 1/2") or a router table so the full length of the cutter can be used. Consequently, because of it's extreme ease of use, no more dropped or damaged cutters or frustration will result when changing tools. The body of the new Musclechuck™ assembly is slotted in such a way that allows the tool shank to be held circumfrentially, when the cap screw is tightened. In the past most quick change chucks relied on one or more cams to retain the tool shank. However, the Musclechuck™ assembly doesn't contain a cam and because of it's superior holding capacity, larger cutters can be held more securely without damaging the shank of the tool.