*This laser sight is made of high-strength aluminum alloy, strong and durable. Has a good shelf life*This laser is very powerful and can be seen with the naked eye at distances up to 100 meters*The rail of the red dot laser sight is 20mm. Product Dimensions: 57mm x 19mmFit 20mm (0.79"e;) RailEasily attaches to handguns and pistolsCompact, lightweight, durable.Increase your accuracy, confidence and sight while shooting.