Dimensions: 13 x 38 x 19 mm (W x L x H); Internal dimensions: 37 x 12 mm (L x W). Note: The inner opening has a baffle. Usage: Rectangular chair leg caps make it easy to move and without noise by installing them at the bottom of the application, such as chairs and desk legs. Fits 1.3 x 3.8 cm outer diameter rectangular tubes (no hole size). Designed to fit 13 x 38 mm (outer diameter) rectangular tubes. Function: The black ridged plastic caps are perfect for preventing scratches on kitchen or wood floors or as protective pads on chair tips, bench legs, table legs, bar stool glides, patio furniture inserts, and much more. They are also designed to withstand impact and harsh weather conditions. Wide Application: Black tube inserts serve as a durable solution for many household or outdoor projects, including replacements for fence/fence posts, gate post covers, trailer frame ends, pipe post rod caps, metal bike rack fittings, forged steel finishing plugs, or any square opening. Color: Black Quantity: 20 pieces Lonvre