Digitrax DCC Decoder - TL1 - Single Function Decoder... Product Information: 4 Wire - Single Function Decoder, Function can be turned on/off using F0, F1, F2, F3, or F4 and Supports both 2 digit and 4 digit addressing... Other Product Information: Function only DCC decoder with transponding, Function only DCC decoder without transponding, Programmable from DCC compatible equipment, Configurable Strobe feature lets you simulate flashing lights like FRED, Strobes, Mars Lights, etc., Compatible with Digitrax DCC Transponding Systems and Approximate size: 0.461" x 0.31" x 0.161" (11.7mm x 7.8mm x 4.1mm).