Sealey cordless circuit tester buzzer led sealey ak415 suitable for testing dc circuits with voltages between 3 and 28volts no earth clips to get tangled simply contact the wire to be tested and touch your finger on bare metal ground to get a reading tester illuminates led buzzes and vibrates on contacting live wire computer safe for use around delicate engine management systems supplied fitted with 2 x long life n sized cells sealey ak415 cordless circuit tester buzzer led