Vortex Optics Venom Red Dot Sights | Auto-Brightness Mode, Ten Brightness Levels, Top Load Battery, Waterproof, Shockproof | Unlimited, Unconditional, Lifetime Warranty Vortex Optics Venom Red Dot Sights | Auto-Brightness Mode, Ten Brightness Levels, Top Load Battery, Waterproof, Shockproof | Unlimited, Unconditional, Lifetime Warranty