These cartridge pumps are equipped with the Ultima electronic float switch with patented Mirus field effect detector cells for problem free automatic operation. Easy-to-install Dura-Port discharge ports eliminate stress cracking caused by over-tightened hose clamps. Pumps include both a straight and a 90 degree smooth elbow and a removable check valve. Made in USA. Available in 4 sizes: 500, 750 and 1000 GPH which take 3/4" hose and 1250 GPH with 1 1/8" hose port.