The Butler Creek Flip-Open Scope Cover provides ultimate lens protection for hunters and shooters with its custom fit design and watertight airtight seal that opens instantly with just a thumb touch.Butler Creek Flip-Open Scope Cover - Size 31 Objective1.998" diameter fit for objective lensesSilent spring hinges for stealthy operationWatertight and airtight seal keeps out dust and moistureTested to -40 degrees Fahrenheit for extreme conditionsTruly ambidextrous designCustom fit to scope for secure protectionPerfect for hunters and shooters who need reliable lens protection in extreme conditions allowing quick target acquisition through narrow windows of opportunity while maintaining complete protection when not in use.