For use in 2 or 3 Wire Circuits ACCURACY GUARANTEED Electromechanical meters only - USE ON 120 OR 240 VOLTS Weatherproof - Industry standard | Plugs in to any 4 terminal meter socket | Rated 240 volts | Use on circuits up to 200 amps California Type Approval for Single Phase watt-hour meters (S-02S-20023 & S-02S-20023E) only Also available in 400 amp "K" Meter - no CT's required!