Lionel 681603 6-81603 O Lion Chief 72-Watt power supply 4 amp for LionChief Sets

LIONCHIEF 72-WATT POWER SUPPLY (4 AMP)

Lionel 6-81603 Power Supply 72 Watt 4 Amp Power Supply for LionChief Sets

You will need a Lionel 637110 6-37110 O LionChief Terminal Fastrack as a terminal track to plug this power supply into. 

Lionel 6-81603 LionChief 72-Watt Power Supply 4 AMP Manual:

Lionel Wall Pack Power Supply