Usage Tips:Features：*High quality replacement piston, suitable for piston air compressors and air pump pistons.*The whole machine has simple and compact structure, light weight and flexible movement.*, anti‑corrosion, anti‑, anti‑oxidation, high temperature resistance, wear resistance.*The function of the piston ring is to maintain the air tightness between the piston and the cylinder wall.*With standard inner and outer diameter size, it is convenient to install and disassemble.*The has no casting defects such as cracks, pores, looseness, etc., ensuring tight connection.*The kit contains 1 piston + 3 replacement piston rings + 1 Pin + 2 Circlip, which can replace the old or damaged ones on the air pump at any time.Specifications：*Product name: Air Compressor Piston + Piston Ring*Material: Metal*Color: Silver, Black*Size: (Optional ) 42mm, 47mm, 48mm, 51mm, 65mm, 70mm, 80mm, 90mm*Suitable for: Piston type air compressor, air pump piston*Quantity: 7pcs/setPackage Content：1*Air Compressor Piston3*Air Compressor Piston Rings1*Pin2*CirclipNote：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.