The Metrel A1425 Welding Equipment PAT Adaptor has a ø21mm CX25 connection which, when used with a Metrel A1422 Active Three-Phase Adaptors – enables compatible Metrel PAT testers (OmegaPAT, SigmaPAT) to perform earth bond tests, insulation tests, leakage current tests and no-load voltage tests on ARC welding units.