FITMENT: 4 sizes Hydraulic U-Cup Twistor Installation Tools are suitable for 7 Inch – 6. 5 Inch seals (20mm – 165mm). (S) 20 – 30 mm / 0.7″ – 1.187″;(M) 30 – 50 mm / 1.187″ – 2″;(L) 50 – 70 mm / 2″ – 2.75″;(XL) 70 – 165 mm / 2.75″ – 6.5″. FEATURES: 1）High Performance– No need to worry about spending a lot of energy when installing the cylinder rod seal before putting it in with your fingers. The kidney bean-shaped seal installation tool can help you easily complete the seal installation work, reduce your burden and save you time. .