Material: These HO scale train wheel parts are made of alloy material, ensuring long use and wear and tear resistanceHigh Performance: Designed with good rotation, 1:87 Metal Wheels provide smooth movement for your model trains. They also feature shock absorption and low noise operating for a more realistic experienceSuitable for 1/87 Scale Trains:HO Scale Wheel are ideal for 1/87 HO scale train models and scenesUniversal Fit: These wheels are universally compatible 1/87 DC electric train carriages, making them great for modifications or replacementsPackage Includes: Each package comes with 2 pieces of these train wheel parts Size Chart: inner axle length:1.43cm/0.56inch,total length:2.1cm/0.83inch,large wheel diameter:1.191cm/0.47inch,small wheel diameter:9mm/0.35inch,wheel thickness:2.95mm/0.12inch Package Includes: 2 Metal Wheels for Model Train Note: 1.This is not infant toy , please take away from children to avoid eating.2.Please allow slightly errors 1-2cm differences due to manual measurement.