Lais DCC 870009 Stay Alive (Large Rectangle) Re-furnished and in perfect working order Will keep most locos running for 30 seconds Wiring diagram for Hornby TTS Decoders Amazing units, I have around 20 running on my locos. Fit beautifully into diesels and tenders of steam locos. No good for HM7000 decoders as you cannot get the tiny 3 pin plugs.