Item Type: Cylinder Piston Kit_x000D_ Material: High silicon aluminum alloy_x000D_ Cylinder Diameter: Approx. 46mm / 1.8in 1Lightweight high?silicon aluminum alloy, come with strong thermal diffusion ability 2Thermal conductivity increased by 42% compared with the bimetal structure, and has a good thermal fit to the piston and reduces the weight of the whole machine 3Made after one?piece forming, increase the strength of the machine body and improve the surface hardness 4The product greatly improved wear resistance, corrosion resistance and high temperature impact resistance 5Come with strong gas compression ability, surging power, clear thread and smooth knob, not easy to jam 1 x Cylinder 1 x Piston 1 x Piston Circle 2 x Piston Ring 1 x Piston Pin