These are made from aircraft grade aluminum to fit the factory 5 round magazines made by Izhmash for the Saiga 12. They may also fit the 8 rounders, but I don't have one of those to test them with. My main objective with these was to make something I could color code, so with just a glance at my mag pouch, I can see if I am grabbing a mag of slugs or buckshot. And oh, by the way, they also count as a US made part for 922r compliance:
Note the rivet heads in the two on the left. Even if I am fumbling in the dark for a fresh mag, I can tell by feel if I am grabbing slugs or shot by braille. The heads are countersunk on the other side, so they won't interfere with the mag internals in any way. They come coated with an aviation grade zinc phosphate primer; you can rattle can them in whatever color you want. $6 each for the plain (no rivet) floorplates, and $10 each for a floorplate with either one or three rivets. Plus flat rate shipping. If you also buy one of my stocks, I'll throw them in the same package at no additional shipping cost.
Note: If you are looking for fancy, CNC machined floorplates, these aren't them. I cut these to fit using a template; they are each tested to fit in a factory Saiga 12 magazine. I have been using them in my own shotgun for several months and many hundreds of rounds with no problems whatsoever. Once I use up the rest of my on-hand material, that will probably be the last of these, at least for this price.
Here's another picture of them in my magazine pouch to illustrate the color coding. I coded them to match the hulls I am using for reloading: