Small dosing pumps have -priming function, no valves or seals, convenient tube replacement, easy maintenance. Positive and negative support: swap the positive and negative supplies, can reverse the pump-head. The dosing pump is generally used in the fields of experimentation, biochemical analysis, pharmaceuticals, fine chemistry, biotechnology. Motor efficient with a stable performance in output, reduced operation noise, used the clasp without screw for convenient disassembly and assembly. Stainless steel screws, rust corrosion resistance. The pump-head designed for easy disassembly, easy to wash and maintain. Type: B Applicable : direct current 12 voltage Working environment: 0-40 Relative humidity: Less than 80% Pump tube(inner x outer diameter): 3 x 5mm -range: type B: 25-70ml/min Speed range: 0.1-60rpm Current: type B: 250-300mA Motor size: 32 x 23mm / 1.3 x 0.9inch Center distance of installation hole: 48.5mm / 1.9inch color:Black Material:plastic+metal Package Contents: 1 x Peristaltic Pump Only the above package content, other products are not included. Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.