uxcell Spare Parts Air Compressor 51mm Diameter Piston Rings Set 3 Pcs Product Name : Piston Ring;Compatible for : Air Compressor Including : Balance Ring (2 Pcs);Seal Ring (1 Pcs) : Seal Ring (1 Pcs) Diameter : 51mm / 2";Thickness : 2.5mm / 0.1" Material : Metal;Color : Black Weight : 23g;Package Content : Piston Ring Set(3 Pcs)