These pump series consists of four different sizes. The basic version can be combined with either an automatic switch AS888, an electronic float switch or the new ULTIMA switch for automatic operation. The Cartridge Duo pumps are equipped with a non-clogging electronic float switch as standard. For L450, L550, and L650 and dito Ultima Combo versions, we have improved the design with easy-to-install Dura-Port discharge ports to eliminate stress cracking caused by over-tightened hose clamps. The pumps will be delivered including both a straight and a 90° smooth elbow Dura-Port as well as a removable check valve. Both the Cartridge and the Ultima Combo pumps may be manually operated via the bilge control panel. Features Compact, all-in-one motor/impeller unit No tools needed for maintenance Extremely energy efficient Water-cooled motor for long service intervals Meets the international standard, ISO 8849 marinePump body: Thermoplastic Shaft seal: Lip seal Shaft: Stainless steel (SS2343) Voltage: 12/24 V DC Hose sizes: L450 - L650: 3/4" L750: 1 1/8" Consumption: 3AOperation for Ultima Combo version1. When the bilge water rises and reaches the second detector cell at 50 mm (2”), the switch starts the pump, with a 3 second delay. 2. When the water level has sunk to a level of 20 mm (3⁄4"), and the first detector cell is above the water level, the pump is stopped.