This Package Contains Two Sets of HO Scale 100 Ton Roller-Bearing Trucks by Atlas Model Railroad Company. FEATURES: Black plastic trucks with free-rolling metal wheels. Fits #2-56 screws. Compatible with any HO scale model railroad equipment. INCLUDES: Two Sets of HO Scale 100 Ton Roller-Bearing Trucks. REQUIRES: HO Scale Model Train Equipment. Adult Supervision. SPECS: Scale: HO 1:87 Length: 1-1/4" (32mm) Width: 1-1/8" (29mm) Height: 3/8" (9mm) COMMENTS: Keep small parts away from children under 3 years of age. sdw 2/1/01 ir/jl