This is a compact size submersible water pump(none self-prime). It's built by a brushless motor providing smooth and quiet operation than a non-brushless water pump. Note: 1. It can be used in the water or other liquids(without particles and impurities); NOT for acid and alkali solution. 2. DO NOT dry burn the pump, otherwise it would be damaged; 3. PLEASE let the pump vibrate several times in the water to exhaust air, then it can work normally. Specifications: Color: Black Pump material: ABS Temperature resistance range: 0 ~ 100°C Condition of use: Continuously Power consumption: 2.3W Rated voltage: USB DC 5V  Max. flow rate: 220L/H Max. lift: 250cm / 8.2ft Noise: Less than 35dB Outer diameter of inlet / outlet: 9mm / 0.35in Inner diameter of inlet / outlet: 6mm / 0.24in Waterproof class: IP68 Product size: 56 * 52 * 47mm / 2.2 * 2 * 1.8in  Product weight: 83g / 2.94oz Package size: 6.2 * 6.2 * 4cm / 2.44 * 2.44 * 1.57in Package weight: 93g / 3.28oz Package List: 1 * Brushless DC Pump 1 * Adapter Plate