Paige,
This box is about 7.25 inches wide across the bottom. It is made to store the smaller sized metal enamel pins. If you wanted to store EW's larger resin pieces in it you can probably fit 2-3 brooches depending on the designs. However you could only store rather flat brooches in it because the foam inside these boxes is thicker than the foam in a standard brooch box. Any brooches that are too thick will touch the cover of this box or keep it from closing which could damage a resin brooch. I wouldn't recommend it for the resin brooches for this reason.