This is a Regal Beloit Century Centurion B2853 Square Flange Up-Rated 1 HP Pool and Spa Pump Motor, 3450 RPM, 115/230 Volts, 56Y, Threaded Shaft.
Century motors by Regal have been carefully engineered to meet the rugged demands of the pool and spa industry. They are the innovative leader in pool pump motors.