Madico 12 pc Stackable Multi-Height Stabilizing Rubber Wedges - Super-Grip Hold on Hardwood, Tile, Carpet Easy fix for wobbly tables or chairs due to uneven floors or furniture Soft rubber wedges that grip on almost any surface to stabilize furniture or hold doors open Stackable - put 2 or more together for wider threshold gaps, tabs interlock to keep in place Solid rubber bottom with gripper 'nubs' - great for hardwood, tile, concrete or carpet 2"L x 1/2"W x 1/4"H, black; sold in sets of 12 - hole on end for permanent attachment