I have peeps on both the front and rear of a older T/C Hawken percussion, I will try to get a pic tomorrow, the front has a wide selection of inserts. Everything from a post to amber peep to actual peep. The rear has two different inserts one has a very small hole for target shooting the other larger for hunting. Didn't have to do any drilling, I installed these in the middle 70's, if I remember correctly they are made by Lyman. I used this rifle, with these sights, in competition for many years, everything from paper to moving targets and they work great.