Here is a three rail O gauge electrocoupler from Lionel. Theis one is for upgrading your Command equipped F3 and other diesels. Kit works with Engines. Note that some soldering may be required. Comes with instructions.
Includes one coupler.
All releases of the LCRU will operate ElectroCouplers.
From 2000.
CONDITION: C-9 New in Open Box. Box has some rubs.
This kit also requires the locomotive have an LCRU or R2LC command control board (not included).