Fully assembled units fit Tomy streetcars (sold separately) and feature can motor and flywheel. Chassis can operate on curves of 4" 103mm or larger.
 
Unit features two powered axles, and positionable front truck to set overall wheelbase at 1-13/32" 36mm, 1-1/2" 38.6mm or 1-5/8" 41.2mm. Chassis measures 2-5/8" 68mm; truck wheelbase 5/16" 9.2mm.