The Open Neutral Service Tester is designed to detect open-neutral problems that originate anywhere from the very last panel all the way back to the transformer. The tester has an exclusive load feature that makes it possible for a single electrician to test for open neutrals under load. It eliminates the guesswork and cuts the electrician’s time from several hours (and maybe several trips) to about 15 minutes. The product allows electricians to discover open-neutral problems at the meter without breaking the seal. Sure Proof Testing