Sightmark SM19001 56MM Triple Duty Riflescope Sunshade makes great addition to your Sightmark Triple Duty Sniper Riflescope. Sightmark Sunshades are designed to fit Sightmark Triple Duty Riflescopes by selecting the objective lens size. For example, the 56mm Sunshade will work with your Sightmark Triple Duty Sightmark Triple Duty 10-40x56 Riflescope and the 50mm Sunshade will work with your Sightmark Triple Duty 8.5-25x50 Riflescope. All Sightmark Riflescope Sunshades products are protected by a limited lifetime warranty. Sightmark Riflescope Sunshades Eliminates glare in bright Light conditions. They Help Keeps dust and rain off of objective lens for a clean clear shot. limited lifetime warranty.