A pneumatic tool, air tool, air-powered tool or pneumatic-powered tool is a type of power tool, driven by compressed air, supplied by an air compressor. Pneumatic tools can also be driven by compressed carbon dioxide (CO2) stored in small cylinders allowing for portability. Pneumatic tools are safer to run and maintain than their electric power tool equivalents, and have a higher power-to-weight ratio, allowing a smaller, lighter tool to accomplish the same task. General grade pneumatic tools with short life span are commonly cheaper and are also called disposable tools in tooling industries while industrial grade pneumatic tools with long life span are more expensive. In general, pneumatic tools are cheaper than the equivalent electric-powered tools.