HO Gauge Model Train Wheels - 24 Pieces These small (8mm) wheels are perfect for streetcars, narrow-gauge railway vehicles, and the bogie trucks of freight cars. For the truck bearings, you can either cut out 2.1mm (inner diameter 1.65mm) brass pipes (C-pipe OP-577) made by wave, or use bearing metal planes made by KTM. 【Specifications】 - Type: Model train wheels - Quantity: 24 wheels - Material: Metal wheels (axles are plastic) - Wheel Diameter: 8.0mm (as shown in the photo) - Axle Width: 23.2mm (as shown in the photo) - Axle Diameter: 2.9mm in the center, 1.4mm at both ends (as shown in the photo) Thank you for viewing. Vehicle Type...Option Parts Type...Wheels