These round, steampunk-style sunglasses feature variable Neutral Density (ND) filter lenses, allowing you to manually adjust the level of light reduction. By rotating the outer ring of the lenses, you can toggle through different "gears" or levels of tint (typically gears 1-9) to suit various lighting conditions. 

• Adjustable Tint: Uses built-in ND2-400 filters to darken or lighten the lenses manually.
• Protection: These glasses typically offer UV400 protection and feature polarized lenses to reduce glare from surfaces like water or roads.
• Design: They are characterized by a retro, round metal frame and thick, camera-lens-like adjustable rims.
• Utility: Ideal for activities with highly variable light, such as photography, fishing, driving, or outdoor sports.