precision, flow liquid delivery: The unit supports a flow range of 0400 ml/min for accurate quantitative liquid delivery in aquariums, laboratories, analytical instruments, and other applications. Flow direction is controlled by switching between positive and negative poles. Optimized roller structure for easy hose replacement: A calibration roller design makes hose replacement straightforward, preventing pinching or breakage due to inexperience and enhancing safety. Quiet and durable roller system: The roller uses quality ball bearings for quiet operation and long life, and stainless steel screws provide rust and corrosion resistance. Quick assembly and disassembly for efficiency: The handtightening pump cover allows fast assembly and disassembly, facilitating hose replacement and maintenance. It can be used with a variety of motor types for constant or variable speed operation to meet diverse needs. Use scenarios: Aquarium dosing: Precisely add nutrients, medications, or other additives as part of an automated maintenance or supplementation routine. Laboratory or analytical instrumentation: Deliver calibrated volumes of reagents or samples for experiments, assays, or instrument calibration. Research and process control: Support consistent liquid delivery in development, testing, or production environments where adjustable speed and easy maintenance are beneficial.