Adjustable Pressure Industrial Spray Gun and Stepped Tip Design for Easy Heater Core Flushing. The tip fits 1/2", 5/8" and 3/4" hose fittings. Water pressure can be easily controlled with one hand by squeezing the handle of the heavy-duty spray gun. The insulated handle protects your hand when using hot water to flush the cooling system. The spray gun attaches to a standard garden hose.