Grease guns dispense grease on equipment where a permanent lubrication system can't be attached, such as automobiles, farm equipment, and some industrial machinery. They keep parts well lubricated and help extend the life of the equipment. Grease guns also allow grease to be applied exactly where needed to avoid waste. Air-operated (also called air-powered or pneumatic) grease guns require less effort to operate than manual guns and are less likely to run out of power than battery-powered guns. They're well suited for large-scale lubrication tasks. Cordless battery-powered grease guns are more efficient and require less effort to use than manual guns. They're also more portable than air-powered guns, making them ideal for applications where machinery must be maintained in the field. Manual grease guns dispense grease with a simple hand pump and are suitable for applications with low fill volumes and few lubrication points.