kadee 555 self centering roller bearing trucks 1pr

Self-Centering Trucks Roller Bearing w/36" Smooth Back Wheels (Diesel-Era) These special trucks make it easier to get your freight cars back on track. When you pick up the car and hold it level and upright, the trucks swing and align themselves along the axis of the car. The conversion adds additional weight and provides a low center of gravity to aid in tracking.