precision, flow liquid delivery Flow range: 0400 ml/min, suitable for quantitative liquid delivery in aquariums, laboratories, analytical instruments, and other applications. Flow direction control: can be switched between positive and negative poles to direct flow as needed. Optimized roller structure for easy hose replacement Calibration roller design simplifies hose replacement. Reduces the risk of pinching or breakage caused by inexperience, enhancing safety. Quiet and durable roller system Roller uses quality ball bearings for quiet operation and long service life. Stainless steel screws provide rust and corrosion resistance. Quick assembly and disassembly for efficiency Handtightening pump cover enables fast assembly and disassembly. Facilitates hose replacement and maintenance. Compatible with a variety of motor types for both constant and variable speed operation to meet diverse needs. Use scenarios Aquarium dosing and precise water changes requiring accurate flow control. Laboratory liquid handling for quantitative delivery to reactions, instruments, or vessels. Analytical instrument workflows that require repeatable flow and the option to run with constant or variable speeds.