Support CW and CCW: Switching power supply positive and negative pole, realize the CW and CCW of the pump head. Flow direction: You can control the flow direction by the positive and negative connect. No valves and seals, convenient hose replacement, easy maintenance. This small dosing pump has the function of self-priming. Widely used in the field of experiment, medical, biochemical analysis, pharmaceuticals, fine chemicals, biotechnology, food, environmental protection, family, etc. Specifications: Model: G328 Color: Black/Green(optional) Silica Gel Tube(internal dia.*outside dia.): 1mm*3mm/2mm*4mm/3mm*5mm(optional) Motors: DC12V Flow Rate: 1*3 silica gel tube: >11ml/min 2*4 silica gel tube: >39ml/min 3*5 silica gel tube: >80ml/min Pump Head Material: ABS Pump Pipe: Transparent silicone pipe Pulsations: Three roller Package Size: 7.0 * 6.0 * 4.5cm / 2.8 * 2.4 * 1.8in Package Weight: 82g / 2.9oz Package List: 1 * Peristaltic Pump