I had never heard of this company before but they were included in a recent Eduard P-51B kit. These are plugs of flexible EVA foam that you just slide into the opening of the wheel well prior to painting the outside color. The foam can be a number of colors. The color does not really matter, they work regardless of foam color.
To say I was skeptical would be an understatement. I tried a set recently on my two models and found them to be excellent. They are push fit into the opening and are reusable. So, if you build multiple kits of the same airplane you’ll find these little plugs to be an investment that will save you lots of masking time.
This particular set is designed for the Eduard FW-190A-5 and A-6 kits, kit # 82143, 82149, 82148 although I can’t see why they wouldn’t fit the A-7, A-8 and possibly the D-9. They are all the same shape of wheel well opening.