Universal Compatibility:This HO scale train speaker is designed to be fit for a wide range of model trains, making it a versatile addition to your collectionMaterials:Crafted from quality alloy and pp material, this train accessory ensures long term performance and reliabilityCompact Size:With a diameter of just 2cm, this small speaker is great for fitting into tight space within your model train setup without compromising sound qualitySingle Unit Packaging:Each purchase includes a piece of the train speaker, allowing you to expand your model train audio system as neededEnhance Your Model Train Experience:Upgrade your electric trains with this easy to install speaker, adding realistic sound effects that bring your miniature railway to life Size Chart: Diameter:2cm/0.79inch Package Includes: 1x HO scale train speaker Note: Please allow slightly errors 1-2cm differences due to manual measurement.