This is a heavy duty, 1/2" NPT blow gun with a capacity of 170 CFM @ 100 psi (3" long nozzle). It is used in various mills or industrial areas where an ordinary blow gun does not provide enough flow. The OSHA approved safety tip has relief holes in the event the nozzle is blocked. Safety blow guns have safety tips which prevent the buildup of tip pressure in the event the outlet is obstructed (complies with OSHA 1910.242B & 1910.95 requirements when used on an airline of 150psi or less). The safety tip has a hole to allow the air to vent.