HoodEYE 3.0 is designed for use on the HoodLoupe 3.0 for improved LCD screen viewing. The hypoallergenic silicone rubber HoodEYE is an oversized eyecup with a temple flair that does a great job of sealing out all light when outdoors. A slip ring mount allows for diopter adjustment with the eyecup pressed up to your eye. Right or left eyed does not matter...simply rotate the HoodEYE to where you want it. Mounting HoodEYe is a snap...pull the original eye cup from your HoodLoupe and mount the HoodEYe 3.0 in its place.