AES Industries 18500 Pneumatic Spark Plug Cleaner with 4oz Bag of Cleaning Abrasive GENTLY removes carbon build-up on standard size spark plugs, revitalizing them for improved performance. INCLUDED is a 4oz bag of silica free cleaning abrasive and Complete Instruction & Maintenance Sheet with Images. 1/4" NPT (Female) air inlet with hose barb for installing a 3/8" air line directly to the cleaner. (Hose barb can be easily removed and replaced with a 1/4" NPT quick fitting or coupler for easily attaching and detaching your supplied air line.) Keep in mind that this cleaner needs 90 PSI to properly operate. SIMPLE TO USE: Position the side abrasive lever down to allow AIR and ABRASIVE to swirl around and gently clean the spark plug and position the lever up to allow only AIR to flow around the cleaned spark plug and remove the cleaning abrasive before taking the spark plug out for visual inspection. PROPER SETUP of this machine is key to this spark plug cleaner properly operating for you. It MUST be mounted VERTICALLY to a wall or post with the spark plug insert grommet facing up.