This ingenious white plastic device incorporates a 20oz. Bottle that acts as a reservoir for the unit. Just press the button and a fresh supply of water fills the bowl for a clean water basin in the studio, field or classroom. When your water is dirty just press the button again. The dirty water goes to the bottom of the unit and fresh water replaces it. You get about 8 to 10 water supplies per sitting. When done just pour out the used water from the bottom unit, wipe clean the basin and fill up the bottle with water. Rinse Well will make painting more pleasurable and insure that your colors are free from contaminates.