Raw brass. 3.5 Inch. This is the base I have used most frequently for many years. You can collage with metal leaves and flowers which can be colorized with our markers sold on the site (or spray paint, acrylics or Pebeo)or do a mix of beautiful old stones to make a pave'd centerpiece. I like to take buttons and old hardware to make an interesting found item necklace. It's up to you! There are holes at either end to attach chain or beads and a slotted opening front and center. Sold by the piece, ***about three and a half to four inches across***and a bit smaller than the ex large crescent.