CNC machined out of 6061 aluminum. The Optum sunshade is designed with multiple steps and groves to act both as a reducer and limit glare. 

Specifications

• 1 Step does not reduce inside diameter, features white centering ring
• 2 step reduces insider diameter of a 40mm scope to 35mm or a 35mm scope to 29mm, features two white rings
• Long does not reduce inside diameter and instead features an internal taper to eliminate tunnel effect, will only thread into target side of 35mm Optum scope
• The MDR or Metal Decal Ring, does not reduce diameter, simply offers a white centering ring