The 4 modules selector switches are designed for DIN rail installation in enclosures or cubicles. The ammeter selector switch uses a single ammeter (by means of current transformers) for successive measurement of the currents of a three-phase circuit. Electrical durability of 1,000,000 operations, and mechanical durability of 2,000,000 operations for an utilization category type AC21A-3. This product is calibrated for 10A circuit rating. 4 contacts for phase 1, 2, 3 or none. Complient to standards IEC/EN 60947-3. Ingress Protection IP66 on front, and IP20 on the back at terminal level. Product dimensions are 60mm in height, 36mm in width and 75mm in depth.