Please note: For the correct size, you need to measure the outer dimension of the leg. This cap is delivered as a straight cap and you have to cut off a piece yourself to make it fit. Product InformationSize Chart for Insert Cap Rectangular with Felt for Angled Legs Outer Dimension (mm) Inner Dimension Short Side (mm) Inner Dimension Long Side (mm) 20×15 10,5 – 13,5 15,5 – 18,5 25×15 10,5 – 13,5 15,5 – 22,7 25×20 12,1 – 18,5 17 - 23 30×10 6,2 – 8,8 25,6 – 28,1 30×15 10,8 – 13 25,8 – 28 35×15 9,7 – 13,1 30,3 – 33,1 35×20 13,5 – 18,5 28,5 – 33,5 40×10 5 – 7,5 34 – 37,5 40×15 10 - 13 34 – 37,5 40×20 15 - 18 34 – 37,5 Material: Cap - PE (Polyethylene), Felt – PEs (Synthetic needle felt)Color: blackInstructions for Cutting to Size1. Remove the old cap from the leg.2. Place the new cap next to the old cap.3. Cut the new cap to size so that it matches the old cap. This is easiest with a sharp utility knife.4. Place the new cap in the chair and protect your precious floor!