Before my eyes gave up playing I use to use WILLIAMS peep sights on several rifles. All are LIGHT, CHEAP, RUGGED & work well and you can change the APERTURE to whatever you want for size. I had the BRASS circle which worked well but if I did it again I'd opt for the IRIS type that opens/closes so you can alter the diameter of the hole just by turning the rim of the sight. This makes a BIG difference on how sharp the front sight/target is. Wonderful tool. The WILLIAMS also allows for FINE repeatable adjustment for DISTANCE & WINDAGE. I've used Skinner and they are also great but JUST MY OPINION is the adjustment wasn't as precise/repeatable. You won't go wrong either way, both are nice but for my $$$ I prefer the WILLIAMS.