GF Signet P51530-P0: Paddlewheel PP 1/2-4 inch pipe. Specifications: GF Signet Type 515 Rotor-X Standard Mount Paddlewheel Flow Sensor, self-powered, Black PVDF Rotor, Polypropylene body, Titanium pin, 1/2-4 inch (DN15 to DN100) pipe size.