This full featured BEMF, 6-function decoder is designed specifically for HO Scale locomotives equipped with a 21-pin inline socket for DCC, such as On Track Models, Auscision and Southern Rail Models. Included is the TCS next generation BEMF for outstanding slow speed performance, quiet drive for super quiet engine performance, and auto adjusting motor control for hassle free set-up.Dimensions: .78" X .59" X .13" or 20 mm X 15mm X 3.5mm.Will easily plug into any locomotive with a 21 Pin Socket.Suitable for just about any HO scale locomotive.This decoder is covered by the TCS Goof Proof one year, no questions asked warranty.TCS  will repair/replace the decoder even if you accidentally damage it. Decoders should be sent directly to TCS and will be repaired or replaced at TCS' discretion.  Alternative Decoders  ESU LokPilo t Standard ESU LokPilo t 5