Atlas O Premier 3001777 O Scale Madison Heavyweight Western Maryland RPO 184 MVRY so there is a size

so there is a size perfect for 1/10 or 1/8 scale applications

the New York Central Railroad

Pennsylvania Class M70b Railway Postal Car Kit

each with a 3 by 3 opening

The Hobbywing EZRun Max8 G2 Waterproof Brushless ESC and Motor Combo includes the awesome 4278SD G2 - 2250kV sensored motor to deliver high torque

Atlas O Premier 3001777 O Scale Madison Heavyweight Western Maryland RPO 184 MVRY so there is a sizeAtlas O Premier 3001777 O Scale Madison Heavyweight Western Maryland RPO 184 FEATURES: Durable ABS Intricately Detailed Bodies Metal Wheels and Axles Constant Voltage Overhead LED Interior Lighting Operating Die Cast Metal Couplers Colorful, Attractive Paint Schemes End of Car Diaphragms Separate Metal Handrails Fast Angle Wheel Sets Needle Point Axles Detailed Car Interiors 1: 48 Scale Dimensions Detailed Car Undercarriage Sliding Baggage Car Doors