1. The -pump is by a -DC motor, which drives the internal mechanical eccentric eccentric motion, and the eccentric motion drives the internal reciprocating motion of the diaphragm. 2. In this way, the fixed volume of air in the pump chamber is compressed (the compressed suction port is closed, and the exhaust port forms a slightly open positive pressure), stretched (the compressed exhaust port is closed, and the negative pressure suction port is opened). The pressure difference, at which the gas pressure (suction) enters the pump chamber and is discharged through the exhaust port. 3. -type vacuum pumps are mainly used in electrical products, industrial products, vacuum -keeping machines, automobile exhaust gas reforming equipment, gas analysis and sampling, instrumentation and other fields. Completely maintenance-free, no oil pump, no pollution to the transmission medium, and can work continuously for a long time. 4. Small size, stable and reliable, hand- pump suction instrument, low noise, low power consumption. Especially suitable for high negative environmental requirements. Working voltage: DC9V~14V Rated voltage: DC 12V Rated current: 500mA Rated power: 6W Suction: 5L/min Vacuum degree: 65kpa Maximum pressure: 120kpa Noise: Less than 60db Suitable for 4.5-6mm tube. Mainly about hardness. The largest part of the outer diameter is 6.5mm. color:Black + silver Material:ABS+Metal Package Contents: 1 x vacuum suction pump Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.