your router bits an added 2-1/4 '' when you extend them through the router table intensity with our router collet extension. the insidious temptation of withdrawing the shank from the collet in order to raise the bit and to `` provide the stuffed depth of cut . '' . The router collet extension it feasible to use all diameters of 1/2 '' and 1/4 '' shank bits safely. the router collet extension shank in the 1/2 '' router collet and the router bit shank in the extension collet and tighten both. Instructions. with 1/2 '' collet routers only.