Sitka Gear Bino Bivy Pack/Accessory, Optifade Open Country, One Size. The Bino Bivy is a key addition to the Open Country product line. It is no doubt that your optics are one of the most important accessories in your arsenal. With the introduction of the Bino Bivy, you now have an effective option to protect your optics. A lightweight mesh harness system, handy accessory pockets, silent magnetic closures and DWR soft shell fabric make the Bino Bivy the ultimate in padded optic protection.