The Mth 20-2027-3 Southern #6902 Alco PB Powered B Unit is a ready-to-go pre-built model train in 1:48 scale, featuring a green color scheme and made from plastic and diecast materials. This diesel locomotive from the MTH brand represents the Southern corporate roadname and operates on an analog control system with a motorized feature for linking to the A unit's reverse system. Ideal for collectors and hobbyists aged 17 years and up, this O gauge locomotive is a great addition to any model railroad setup.