Features:*The function of the piston ring is to maintain the air tightness between the piston and the cylinder wall.*With traditional inside and outer diameter size, it is convenient to put in and disassemble.*The for has no casting defects corresponding to cracks, pores, looseness, etc., guaranteeing tight connection.*The equipment contains 3 replacement piston rings(Including 2pcs stability ring+1pcs seal ring), which can replace the old or broken ones at the air pump at any time.*Suitable for air compressors and air pumps with a cylinder diameter of 42mm/47mm/48mm/51mm/52mm/65mm/90mm/95mm/100mm, and wish to get replaced when the axial clearance is larger than 0.13mm.Specifications:*Item Type: Air Compressor Piston Ring*Compatible for: Air Compressor*Size: As photo show*Applicable cylinder diameter: 42mm 47mm 48mm 51mm 52mm 65mm 90mm 95mm 100mm, Please Choose the right size.*Quantity: 3pcsPackage Contents:3 x Air Compressor Piston RingNote:1. The real coloration of the object could also be barely different from the pictures proven on web page caused by many points resembling brightness of your display screen and lightweight brightness.2. Please enable slight handbook size deviation for the data.