This is a start capacitor that allows your pump motor to cycle between on and off more seamlessly, which allows your motor to run more efficently. Features: Microfarad Rating: 324-388 mfd Motor Parts Type: Capacitor, Start Length: 2-3/4" Part Dimensions: 1-7/16"dia x 2-3/4"h Diameter/Width: 1-7/16" Capacitor Microfarad Rating +/- 10%: 324-388 mfd Electrical Connection: 1/4" tab Voltage: 115v