I made my own, took a piece of naugahide glued to a bent coated paper clip, the plastic on the clip protects the lens, punched the smallest hole on my multipunch pliers. Just clip to my glasses n shoot the sights and target are very clear even at 100 yds. the soft side of the hide protects the lens too, even used it to get my doe opening day, helps to see brush ect. in the bullet path. Got her at 45 yds. man that 54 cal ball hits hard, took both lungs and destroyed the exit shoulder, she still ran 40 yds uphill then dropped.