1L Foam Cannon for Car & Exterior Cleaning. Enhance your vehicle cleaning experience with our 1L Foam Cannon, designed for superior results and effortless operation. Why choose our 1L Foam Cannon?. Easy to Use: Simply mix soap with warm water in the bottle, connect the 1/4″ plug to your washer gun or wand, adjust the top knob, and watch as thick foam dispenses with ease.