OverviewBig Timber features low-light capability with full sun protection in a single lens. With a full wrap and our Auto Sun lens, Big Timber is ready for the days adventure, even if it's early or late. Auto Sun is designed for days outside in changing light conditions. Photochromic technology automatically adjusts from a low-light, bright yellow with a 28% Visual Light Transmission (VLT), to a high visibility persimmon with a 15% VLT for sunny conditions, while polarization protects and heightens color, definition, and detail. Zeal Optics frames are made from Z-Resin, a unique plant-based polymer derived from the castor plant. This durable plant-based material contributes to a lighter weight frame, for more comfortable everyday wear and activities.