This is an HO scale (1:87 proportion) model of an Electro-Motive Division GA8. The GA8 was a narrow gauge diesel-electric roadswitcher designed for export to foreign countries.
Included is an adapter piece to create an HOn30 model using a Bachmann N scale F7 as the drive mechanism. Coupler pads are provided for body-mounting Kadee HOn3 knuckle couplers.
The GA8 body is also available without the adapter piece here.
Thanks,
Damin.