A heavy-duty foam applicator gun is a professional metal dispenser designed for controlled, precise application of pressurized canister polyurethane expanding foams. Built with a durable metal body, stainless steel barrel, and a universal threaded basket adapter, it provides an airtight seal with standard gun foam canisters. It features an adjustable brass flow control knob at the rear to regulate bead size and material output, reducing waste and allowing clean, targeted dispensing into wall voids, door frame gaps, and pipe penetrations.