This router collet extender will allow your router bits to extend an additional 2-1/4” letting you change router bits from above the table, without any special wrenches or a router lift. Even with a lift, bit changes are much easier because the insert ring will not need to be removed. No need to ever again withdraw the bit shank from the collet to get a full depth of cut. Designed for 1/2 inch router collets and for 1/2 inch shank bits. To use simply place the router collet extender in any 1/2" router collet, insert a router bit shank in the extension collet and tighten both securely. Instructions included. .