The Oakley Flak 2.0 XL has been an Oakley staple for years now. It's predecessor, the Flak Jacket XLJ, was already a great frame and Oakley fine-tuned it to make it even better! The 'XL' refers to the taller lenses which provide more coverage, but there is also a Flak 2.0 (non-XL) with the exact same frame chassis and slightly shorter lenses. Oakley Flak 2.0 XL sunglasses are constructed with Oakley’s proprietary O Matter™ for amazing durability and ultra-lightweight comfort. Unobtainium® earsocks and nosepads and Oakley’s Three-Point-Fit system help keep your glasses securely in place even if you break a sweat. If you are interested in using these for a particular sport, you should really check out PRIZM™ lenses. These are sport-specific lenses that boost contrast and allow you to perform at your best! Need prescription Oakley Flak 2.0 XL sunglasses? Done. Call or chat with our friendly Sports Opticians if you have any questions about ordering Oakley Flak 2.0 XL prescription sunglasses. And as always, we offer free shipping & returns!