Features:1. The direction of flow of the peristaltic pump depends on the connection way of positive and negative.2. Ball bearings in the wheel frame, silent, long life time.3. The self-priming viscous pump head designed for easy disassembly, easy to clean and maintain.4. This vacuum pump is suitable for aquarium, chemicals, liquids and other dosing additives.5. Simple design, easy to install, convenient to use.6. Can be equipped with constant speed DC geared motor, stepper motor (adjustable speed) and synchronous motor, long motor life, low noise stepper motor.Specification:Condition: 100% Brand NewItem Type: High Flow Peristaltic PumpWorking voltage: 6~30VWorking Environment: 0-40Relative Humidity: 80%Medium Flow: the flow direction of the pump depends on the positive and negative connectionFlow Range: 0 - 400ml / minTube inner diameter: 6.4mm / 0.3inchTube outer diameter: 9.6mm / 0.4inchWall thickness: 1.6mm / 0.06inchMaximum Diameter: 9.6mm / 0.4inchTube Material: Transparent silicone tubeShell Material: PCRoller: 304 stainless steel wheel frameRoller type: Ball BearingPump Cover: Hand screw, quick release for easy tube replacementPackage List:1 * Peristaltic Pump1 * Hex WrenchNote:1. Please allow slight error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard..