The onn. Electronics Duster Compressed Gas Cleaner is a 2-pack of 10 oz cans designed for cleaning electronic and camera equipment. It is ideal for use on computers, keyboards, mice, printers, copiers, TVs, photo equipment, stereos, audio equipment, sewing machines, cash registers, lab equipment, clocks, watches, and musical instruments. To use, remove the small tab on the spray nozzle, hold the can upright, and pull the trigger to clear the valve. Then, hold the can 2" away from the item to be cleaned and pull the trigger in short blasts. The extension tube can be used to clean hard-to-reach areas.