Features:1. It helps keep dust from your lens mechanism.2. Made from high impact plastic, duurable enough for long time use.3. This rear len cap is used when storing your lens or after the lens has been removed from your camera.4. Suitable for all Canon DSLR Lens5. It helps to store your camera body and the lens, after it is removedDescriptions:1.Fits for M42 lens.2.To prevent the lens from damage and scraping.3.The product Package Included: a rear lens cover.Specifications:Material: PlasticInside diameter: 42 mmColor: BlackPackage Included: a rear lens cover.Notes:Please allow 0-2mm error due to manual measurement, thanks for understanding.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Please understand, thank you!