4.Humanized design: The convenient design, the red and white screws rotate synchronously with the pump, allowing users to easily and intuitively confirm the rotation direction of the pump. 1.Essential tool for seasonal inspections: This circulation pump rotation tester is very useful at the beginning of the heating season, allowing users to verify the operation of the circulation pump and identify possible blockages after a long period of inactivity. 2.Versatile: In addition to testing the circulation pump, the device can also check the operation of the oil burner solenoid valve, making it a versatile tool for a variety of heating applications. 3.Clear indication system: The built-in indicator can effectively display the magnetic field and rotation direction of most circulation pumps, instantly displaying the pump's performance for quick diagnosis. 5.Compact and portable: This tester is small and portable and can be hung on a keychain. It is a must-have tool for every plumber or heating contractor to quickly check the operation and rotation direction of the pump., Weight: 0.03968320716 Pounds, Manufacturer: Tuidzljd