air tool(A pneumatic tool or air tool is a tool driven by a gas, usually compressed air supplied by a gas compressor. Pneumatic tools can also be driven by compressed carbon dioxide (CO2) stored in small cylinders allowing for portability. Pneumatic tools are commonly cheaper and safer to run and maintain than their electric power tool counterparts, as well as having a higher power-to-weight ratio, allowing a smaller, lighter tool to accomplish the same task. WAD Alexander Demidov)