Features: brand new and high quality Micro-pump is mainly used for medicines, gas analysis sampling, instrumentation and other fields. Completely maintenance-free, and no oil pump, do not pollute the transmission medium. Micro-pump is powered miniature for DC motor drive, drive internal mechanical eccentric eccentric motion, driven by an eccentric movement inside the diaphragm reciprocates. Small, stable and reliable, hand-held instrument for pump-priming, low noise, low power consumption. Especially -suitable for high negative environmental requirements. Suitable for 4.5-6mm tube. Mainly about the hardness. The largest part of the outer diameter is 6.5mm. Whereby the pump chamber fixed volume of air compression (compression suction port is closed, the exhaust port is formed to open slightly positive pressure), stretching (compressed exhaust port is closed, a negative pressure sucking mouth open), the pumping air intakes with the outside atmospheric pressure difference, at a pressure difference, the gas pressure (suction) into the pump chamber, and discharged from the exhaust port. Specifications: Material:Plastic + Aluminum Operating voltage: DC9V ~ 14V Rated voltage: for DC 12V Current Rating: 500mA Power Rating: 6W Suction capacity: 5L / min Vacuum degree: 65kpa Maximum pressure: 120kpa Noise: <60db Size:Approx. 8.5x6 for cm/3.34x2.36 inches Package Includes: 1x Vacuum Pump note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.