The C-UL US listing mark has been placed on the HypotULTRA III line of advanced hipot testers. Underwriter's Laboratories, an independent not for profit product safety testing and certification organization is one of the most recognized safety agencies in the world. The UL Listing number that HypotULTRA III has received is E204261; this means that the HypotULTRA III family has been tested to and passed all the specifications called out in UL 3111. The Canada/U.S. listing mark complies with regulations for both countries.