ESU 59814 LokPilot 5 micro DCC/MM/SX/M4, PluX16 NEW in original packaging
£32.35
The versions with Next18 or PluX16 interface are a bit larger with a base area of 13.0mm x 9.2mm, but they also speak for the mfx® compatible M4 protocol. The LokPilot 5 decoder can be used on analog DC trains.