Features Lightweight high‑silicon aluminum alloy come with strong thermal diffusion ability Compared with the bimetal structure, the thermal conductivity is increased by 42%, and possess a good thermal fit to the piston and reduces the weight of the whole machine One‑piece forming, increase the strength of the machine body, improve the surface hardness Greatly improved wear resistance, corrosion resistance and high temperature impact resistance, more assured to use Strong gas compression ability with surging power, clear thread and smooth knob, not easy to jam Specification: Item Type: Cylinder Kit Material: High silicon aluminum alloy Cylinder Diameter: Approx. 44mm / 1.7in Package List: 1 x Cylinder 1 x Piston 2 x Piston Circle 2 x Piston Ring 1 x Piston Pin 2 x Plastic Pipe 1 x Bearing 2 x Cylinder Plug 2 x Filter 1 x Liquid Display Device 1 x Spark Plug Package List 1 x Cylinder 1 x Piston 2 x Piston Circle 2 x Piston Ring 1 x Piston Pin 2 x Plastic Pipe 1 x Bearing 2 x Cylinder Plug 2 x Filter 1 x Liquid Display Device 1 x Spark Plug