Constructed of high quality, corrosion resistant 304 stainless steel (Note: Optima has Noryl impeller) Oil lubricated double mechanical shaft seal Air filled, continuous duty motors rated for up to 20 starts per hour Built-in thermal protection with automatic reset (Single Phase Only) Built to operate with full or partial submergence (Optima pumps are available with an optional Low Suction Device) Vertical discharge allows pumpage to carry heat away from the motor Discharge Size: 1 1/4″ to 1 1/2″ Range of HP: 1/3 to 1 1/2 HP Capacity: 4 to 92 GPM Head: 5 to 61 Ft. Max. solid diameter: 3/8″ Max. liquid temperature: 122°F/50°C (140°F/60°C intermittent duty) Available in single and three phase models; manual or automatic operation