Features: High quality replacement piston, suitable for piston air compressors and air pump pistons. The whole machine has a simple and compact structure, light weight, and flexible movement. Resistant to corrosion, oxidation, high temperatures, and wear. The function of the piston ring is to maintain airtight sealing between the piston and the cylinder wall. Standard inner and outer diameter sizes for easy installation and removal. Free from casting defects such as cracks, pores, or looseness, ensuring a secure fit. Kit includes: 1 piston, 3 replacement piston rings, 1 pin, and 2 circlips, allowing timely replacement of worn or damaged parts on the air pump. 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: 7 pcs/set Package Content: 1 x Air Compressor Piston 3 x Air Compressor Piston Rings 1 x Pin 2 x Circlip Note: 1. Conversion: 1cm = 10mm = 0.39inch. 2. The actual color of the item may vary slightly from the images shown due to factors such as monitor brightness and lighting conditions. 3. Please allow slight variation due to manual measurement.