device: 7SL87 differential/distance protection, 1 /3-pole dual-end fault protection, expandable housing type: flush mounting; BI: 99; BO: 49 (43ST + 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 x 19''; modules in 19" row 1: IO 202, PS201, IO205, IO205, IO20 7, IO233; 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,