SF-4 Rotor & Stator Set: Stable Mixing and Reliable Flotation SF-4 cells are chosen for simple, self-aspirating operation. Their rotor and stator set is what keeps the output steady and the spares list short. This polyurethane set is moulded to the original profile and supplied as a matched pair, so the cell is right back to spec after the swap. What you get in the set Rotor, moulded to the SF-4 OEM profile Matching stator with correct working clearance Abrasion-resistant
