This is the ONLY sonic cleaner that has dual technology...UV light and sonic waves for amazing cleaning results. Ideal for dentures, bite plates, retainers, sport mouth guards, invisible braces and whitening trays. Fill the inner-cup with water, place any intra-oral device into the Dental Spa, close the lid, and you are ready to clean and sanitize! Or, choose UV-only and kill 99.9% of germs and bacteria in just minutes. Requires 3 AA Batteries (not included), lifetime bulb. Dimensions: 4.5" x 4.5" x 3.5". Inner Chamber measures 3.75" x 2.75" so some very large dentures or custom devices may not fit. If in doubt, measure before ordering.