The Grundfos SL1.50.65.40.EX.2.51D.C is a Cast iron 4kW, 2-pole waste water pump with S-tube impeller, 50mm solids handling, DN65 flanged discharge port, without sensor, EX rated. The Grundfos SL range are popular cast iron waste water pumps available with either the Grundfos S-tube (SL1 models) or SuperVortex (SLV models) imepllers. The SuperVortex impeller is ideal for waste water laden with fibrous materials, whereas the S-tube impeller is ideal for spherical solids with excellent energy efficiency. The design also features a clamp release allowing the pump to be disassembled without special tools.