... . 4. Easy to operate. 1. Very popular wrist strap tester. Use for test the ESD fuction is ... the round button. the light will show your wrist Strap is good or not.3.Can used ... for test many other items such as ankle strap, antistatic plate, antistatic mat and grounding wire ... convenient to test the grounding system such as wrist strap and ankle strap, antistatic plate, antistatic mat and grounding ...