Power Source: 3V DC (two 1.5V alkaline batteries (not included)) Pump Frequency: 1 600 pulses per minute Water Pressure: Approx. 44 x 10 Pa (4.5 kgf/cm) Operating Time: Approx. 20 minutes Tank Volume: 165 ml Compact for Easy Travel Cordless Convenience Cleans Debris Between Teeth Massages Gumlines Dimensions: 8.9 H x 1.8 W x 2.5 D; Tank Closed: 5.9 H x 1.8 W x 2.5 D Weight: 7.4 oz. (without batteries)