This is a Century SQ1052 Square Flange Full-Rated Two-Compartment .5 HP Pool Pump Motor, 3450 RPM, 115/230 Volts, 48Y, Threaded Shaft.
This motor is used in many Sta-Rite, Red Jacket, Pac Fab and American Products.
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.