Features: The M20 water pumps is compact in size and easy to install in various models. Not only can it be used as a water pumps, but it can also be used as a small air pumps to meet your different needs. The water pumps operates with low noise and is very quiet, without causing any interference to the surrounding environment. Supports 5V power supply, easily powered by 3-4 1.5V batteries(Not included). Simple wiring design: The black square is the wiring terminal, which can be easily disassembled if not needed. Pay attention to the wire connection, with the black wire being the negatives electrode, to ensuring safe and correct operate and avoid the risk of short circuit. Specifications: Component: Plastic Voltages: 5V IN port: 3.5mm OUT port: 3.5mm Connector length: 5mm pumps head length: 18.2mm pumps head width: 14mm pumps head height: 8mm Motor width: 10mm Motor length: 14.5mm Motor height: 8mm Body length: 32.5mm (excluding front and rear raised parts) Water pumps length: 40mm Socket length:15mm Socket width:13.4mm Socket height: 5mm Wire length: About 60mm Package Includes: 1pc Small Water pumps note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.