20 AMP.CURRENT TRANSFORMER RATED. By pass: Plunger type bypass automatically closes when meter is removed. NEMA 3R type construction 1.2mm thickness (#18 gauge) or 1.5mm thickness (#16 gauge) galvanized steel sheet (AISI G90) ,electrostatically applied epoxy baked gray powder finished. Ample gutter space for easy wiring. Convenient knockouts in the side back and bottom. The fixed hub size 1/2″ to 2-1/2″ for option.