FLIP-OPEN COVERSButler Creek's patented "instant action" scope covers have been the number one choice of serious shooters and hunters worldwide for over 20 years. The "Quiet Open" lid opens at the touch of your thumb. The ergonomically designed red button directs your thumb pressure correctly without ever looking. The watertight friction mount anchors the covers securely to the scope while an airtight semi O-ring seals out dust and moisture to protect optics. The spring activated lids perform flawlessly under all weather conditions and extreme temperatures ranging from +120°F to -40°F. Flip-Open covers weigh less than an ounce and are manufactured in sizes to fit all brands and models of scopes. Their superior design serves both right or left handed shooters. (Check catalog page 662 for Sizes).