This collet extender allows you to change router bits from above the table-even without a lift! Even if you have a lift, they still make bit changes easier because you won't have to remove the insert ring. They're also great for custom made router tables with very thick tops, as they provide the additional depth of cut needed for many routing tasks. Use them with our Router Table Spline Jig (#59288, sold separately) to achieve full depth of cut when machining dovetail splines.
Yesterday I bought 3 pieces of Rockler Router Collet Extension for 1/4'' Shank Bits from Rockler at price 29.99. It is useful and top product in this category of additional.