Female national pipe thread x 4.5 mm orifice stainless steel sewer nozzle. Slides easily into drain pipes and sewer lines. Great for flushing debris or clearing frozen pipes while attached to a sewer hose. Forward and backward ports in the nozzle blasts into the clogged pipe, breaking up the debris while pulling the hose through the pipe. Made of corrosion-resistant stainless steel and designed to be small enough to clean in all the tight spaces.