What CAT safety rating should I look for?

For residential receptacle and branch-circuit work, CAT III 600V is the typical minimum. For service panels, industrial three-phase, and utility-adjacent work, CAT IV 600V or CAT III 1000V is recommended. Budget meters often claim CAT ratings that teardown reviewers on EEVblog and similar forums have flagged as not credible — another reason high-trust sources favor Fluke and Klein for live electrical work.