Finger sized, it can be used as both a miniature water pump and a small air pump, making it an good choice for DIY model making Adopting a low-noise design, it runs very quietly and will not interfere with your creative environment Flexible and convenient power supply The pump body is marked with an IN input port, which is compatible with a 3mm inner diameter hose and tightly connected. The wiring terminal is convenient for wiring Please pay attention to the positive and negative poles of the power cord, with the black wire being the negative pole, to ensure proper connection and protect the pump body