Removable Motor Cartridges. 316 Stainless Steel Shaft and Corrosion Resistant Hardware. Easy to Maintain or Replace with Removable Motor Cartridges that Allow Any Capacity Motor Without Removing the Entire Pump.Capability to Upgrade GPH Based On Needs.Resistant to Cracking and Corrosion.Dura-Port Allows Installation Of Hose To Dura-Port Then To Pump Housing Preventing The Twisting Of The Hose.Check Valve Eliminates Pump Cycling.