When I decided I wanted to use plastic boxes for my reloaded 20ga shotshells I looked at the various products being offered. I found these to be made specificially for 20g while some of the others were made for 12 ga and convertable to 20ga. The outside dimensions on these are smaller because of that. They are clear so you can see the contents. I have 11 or 12 of these now with no quality problems with them to this date.