Made from Rubber Material with Multiple Folds and an Ergonomic Eye Cup, Providing Ample Flexibility as Comfortable Cushion and Protection for the Eye Area Against Recoil. Designed to Fit Scopes with Approximately 3'' Eye Relief. Use with Optics to Relieve Eye Strain by Blocking Glare or Enhancing Low Light, and to Improve Focus on Target by Eliminating Distractions from Peripheral Movement. Eyeshade Design Enables Quick Eye Positioning for Proper Eye Relief and Optic Center Alignment to Speed up Target Acquisition and Increase Sighting Accuracy. Adaptor Kit Includes a Lockable Hoop to Secure on Scope's Eyepiece, and 3 Inserts of Varying Thicknesses to Fit on Scopes with Eyepiece Diameter of 36mm, 40mm, 41.5mm or 43mm.