Removable Motor Cartridges. 316 Stainless Steel Shaft and Corrosion Resistant Hardware. Check Valve and 3/4" Straight or 90° Externally Threaded Dura-Ports Allow Multi-Directional Hose Routing and Easy Installation and Prevents Pump Housing Cracking Due To Hose Overtightening. Easy to Maintain or Replace with Removable Motor Cartridges that Allow Any Capacity Motor Without Removing the Entire Pump.Check Valve Eliminates Pump Cycling.