1. Round Wrist Strap Tester 2. Model No.: Airsource-698 3. Very Stable Items for ... production. 4. Easy to operate. 1. Very popular wrist strap tester. Use for test the ESD fuction is good or not ... . Easy to opearte , just plug the Wrist Strap in the tester,Press the round button. the light will show your wrist ... )R<800KNOGood(green)800K R9MYESHigh(red)R >9MNO Wrist Strap Tester