Here is an MTH 40-4000 O Z-4000 400W Dual Control Transformer from 1998. This monster is specifically designed to operate modern-era locomotives and equipment.
Features:
Sine Wave Output
(2) )-22 VAC, 165 VA Variable Outputs
(1) 14V, 1.5-Amp Fixed-Voltage Output
(1) 10V, 1.5-Amp Fixed-Voltage Output
Digital LED Displays For Realtime Voltage & Amperage Readings of the Variable Outputs
Microprocessor Controlled, Smart Operation During Short Circuit Conditions & Expendable Design
(2) Bell Button For Tracks 1 & 2
(2) Horn/Whistle Button For Tracks 1 & 2
(2) Direction Buttons For Tracks 1 & 2
(2) Program Buttons For Tracks 1 & 2
On/Off Power Switch
Large Power On LED Indicator
Large Overload LED Indicator
12 Amp Resettable Circuit Breakers On Track 1 & 2 Variable Outputs
4 Amp Resettable Circuit Breakers For Fixed Outputs 10V & 14V
Expansion Port For Future Upgrades
Internal Cooling Fan For Low Operating Temperatures
Compatible Power Source For All O Gauge, AC-Powered Locomotives
Rugged ABS Construction

This item has been graded per TCA standards C-7: Excellent based on visual appearance. This item displays scratches across each surface, and the control panel has spots of discoloration and adhesive residue. The overall appearance of this item may be improved with a gentle and thorough cleaning. Serial #010105400. The original box is not included. The instruction manual is not included. Please check the photos for a detailed look at this item. Overall condition is Excellent.

Condition: Excellent (C-7)
Operational Status: Functional
Original Box: No

Manufacturer: MTH
Model Number: 40-4000
Years Manufactured: 1998 – ????
Road Name: **** No Road Name

Scale/Era: O Modern
Model Type: Control & Electrical

The SKU for this item is 5968828.

Product Id: 11415165