Sunshades:

Sunshades (available for the 35mm and 40mm Optum) are the easiest way to change your setup in a matter of seconds. Depending on the sunshade model it can provide a centering ring, reduce glare coming from the lens, shrink the inside diameter of the scope, or enable the use of a flip cover. There are three styles of sunshades available for both the 35mm and 40mm Optum scope: the 1-step, 2-step, and long sunshade. Both sides of the Optum scope and all Optum lens housings are threaded to accept Optum sunshades so there are plenty of combinations to consider.

• 1-step sunshade: This option does not reduce the inside diameter of either scope size but it does offer additional protection from stray light and a white centering ring to assist with peep alignment.
• 2-step sunshade: The 2-step does reduce the inside diameter of the scope. A 2-step on a 35mm scope will shrink the inside diameter to 29mm whereas a 2-step on a 40mm will reduce the inside diameter to 35mm. This means you can swap between two scope sizes in seconds by removing or adding a sunshade. The two rings of the sunshade also assists with peep alignment in varying light conditions.
• Long sunshade: If you’re looking for the most protection from the sun then the long sunshade is the way to go. The long sunshade will not reduce the inside diameter and due to a flared interior diameter it will not create a tunnel effect that is expected with long sunshades.