The ultimate eyepiece protection for hunters and shooters, Flip-Open scope covers are custom fit to your scope, create a watertight, airtight seal, and open with a touch of your thumb, so you can put your shot through the narrow window of opportunity in the most extreme conditions. An ergonomic button with a non-slip surface for one touch action operates the fast, flip-open design with a silent hinge to keep your eye on the target and not spook game. It weighs less than an ounce and has been tested to -40 degrees F. The Multi-Flex model features additional flex in the collars to fit a wider range of scopes. The fit range is .01 under and .025 over the listed measurements.