hello-lux rifle scope sunshades are created from lightweight aluminum and decreases unwanted glare and solar reflections off the objective lens. The hello-lux riflescope sunshade comes in 3 diameters: 44mm, 50mm, 56mm. These sunshades are most effective well matched with hello-lux scopes. Those hi-lux sunshades can be threaded into every different to create custom lengths. The 44mm and 50mm sunshades measure 3″ in period. The 56mm sunshade measures four” in period.