device: 7SL87 differential/distance protection, 1 /3-pole dual-end fault protection, expandable housing type: flush mounting; BI: 35; BO: 37 (9ST + 16F + 12HS + 0P); I: 8 (protection); U: 8 ( 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 208, PS201, IO208, IO209, IO20 9, IO209; 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,