PRODUCT DESCRIPTION Simply the ultimate scope lens protection for hunters and shooters. They're custom-fit to your scope, create a watertight, airtight seal, and open with a touch of your thumbs, so you can put your shot through the narrow window of opportunity in the most extreme conditions. Air-tight semi-O-ring keeps out dust and moisture. Tested to -40 degrees F. Truly ambidextrous. Weighs less than an ounce. Also made for spotting scopes. FROM THE MANUFACTURER Simply the ultimate scope lens protection for hunters and shooters. They're 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.