device: 7SD87 differential protection , 1/3-pole dual-end fault protection, expandable housing type: flush mounting; BI : 17; BO: 16 (10ST + 6F + 0HS + 0P); I: 4 (protection); U: 4 ( standard); measuring transducer inputs: 0 (20 m A or 10 V, fast), 0 (20 m A, normal); housing width: 1/2 x 19''; modules in 19" row 1: IO 202, PS201, IO206; modules in 19" row 2: ; LEDs/push-buttons: 16 LEDs; operation panel: integrated; key switch: without; display type: small display; front design: standard; auxiliary voltage: 60 V-250 V DC, 100 V-230 V AC;