Chauvin Arnoux Metrix MX 406B [MX0406B] 50V / 500V Insulation & Continuity Tester. The MX 406 is an insulation and continuity tester for electrical installations and equipment. Designed to withstand the stresses of field use, the MX 406 is an indispensable tool for installers, testing organisations and maintenance services. The remote control probe supplied as standard provides unequalled user comfort:  simply press the probe button to start measuring. The logarithmic scale of insulation values eliminates the need to change ranges while reading. Device supplied with 1 remote control probe, 1 black safety lead, 1 black crocodile clip and a user manual.