Every service technician asks the same question before buying new test equipment. Will this tool help me diagnose or fix the problem faster, accurately, safely, and reliably? The Testo 770-3 clamp meter answers this question directly. Traditional spring-loaded jaws struggle inside tight control cabinets. You often have to pry hot wires apart with your hands. The Testo 770-3 solves this problem completely. It features a unique retractable pincer arm. You can hook individual wires without touching them safely.