The Koolance PMP-450 is a reliable high-flow pump with built-in speed control knob. It handles external control throttling better than the PMP-450S. Maximum Flow Rate: 17L/min (4.5 gal/min) @ 12V, 18.9L/min (5 gal/min) @ 24V Maximum Head Pressure: 4.5m (14.6ft) @ 12-24V Motor: Brushless DC, electronically commutated, spherical motor Expected Lifetime: 50,000 hrs. MTBF (5.7 years) Power: 8-24 VDC, 3-35W, 0.30-1.50A Startup Voltage: 9 to 13.2 VDC Maximum System Pressure: 3.5 kgf/cm2 (50 PSI) Maximum Temperature: 60C (140F) Electrical Connector: 4-pin Molex power supply connection + 3-pin (single lead) tach Hose Connections: 13mm (1/2) ID hose barbs Wetted Materials: PPO, Carbon/Allumina Ceramic, EPDM or Viton, 316 SS Noise: Less than 40dBA Weight: 862g (1.9lbs) General Weight 1.20 lb (0.54 kg) Dimensions 3.50 x 3.25 x 4.00 in (8.89 x 8.26 x 10.16 cm) Diagram - pmp-450_o1.gif Diagram - pmp-450_o0.gif Diagram - pmp-450_d1.gif Diagram - pmp-450_d0.gif