Lionel #41 Vintage O/O-27 Gauge U.S. Army Turbine Powered Diesel Locomotive is a plastic model train for hobbyists aged 17 years and up. It has a Bo-Bo wheel configuration and runs on O/O27 gauge tracks. The locomotive is designed to resemble a U.S. Army train and is in good working condition. The E-Unit has Forward, Neutral, and Reverse respectively. This item is mechanically sound operating. The cab is missing a side rail which doesn't affect the operation of the unit... OVERALL GRADE - VERY GOOD.