Features:*Precise manufacturing, quality assurance.*Complete specifications,long-term use.*With 4pcs Nitrile rubber sealing ring including 2*O-shaped gasket + 1*Catheter gasket + 1*Square gasket.Specifications:*Type: Oil-free cylinder+Piston ring*Material: rubber*Color: Black*Size: As picture show*Types:63.5*69*24.5mm is generally applicable to 550/600W air compressor 63.5*69*47.5mm generally applicable to 750/950/980W air compressor 63.5*69*50mm generally applicable to 1100W air compressor 69*75*47.5mm generally applicable to 1500W air compressor *Quantity: 6pcs/setPackage Includes:1 Cylinder1 Piston Ring2 O-shaped gasket1 Catheter gasket1 Square gasketNote:1.Transition: 1cm=10mm=0.39inch.2. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.3. Please allow slight manual measurement deviation for the data.