This is a feedback module with current sensors for digitally controlled 2-rail layouts. This module can be plugged into the L 88 (60883) with the cable included with the former. The s88 DC has a connecting socket for additional s88 DC decoders (60882). It also has 2 x 8 inputs for current sensors (with optical-couplers) in 2 different power circuits that can be combined into a single power circuit with 16 inputs. The L 88 (60883) is required for connecting s88 units to the CS2 or CS3!