These c-channels are designed to be installed on the bottom of live edge tables. It gets inlayed into the wood using a router. The slotted holes are designed to allow wood to expand and contract and the structure of these is designed to keep the wood from warping while it moves. Lengths: 20'' - $41.00, 31'' - $49.00, 35'' - $54.00, 40'' - $57.00