The Paterson Force Film Washer is a convenient attachment that converts your Paterson roll film developing tank into a film washer. The rubber connector easily slips onto most faucets. The nozzle fits snugly into the reel core of the developing tank. Turn on the wash water and the water flows down the core to the bottom of the tank where it is forced up through the film reels and out of the tank. Simple, economical and effective. Overall length approximately 21". Fits all Paterson System 4 and Super System 4 developing tanks.