The base is 11mm with a 2mm hole for attaching or swedging. The 6 arms are 12mm long. I'm not exactly sure how these were originally intended to be used. But I would use them to wrap around another element. Very interesting in any event. They were found in the famous vintage bead hoard with other Miriam Haskell components. The old ruler is in the photo to give you a better feel for the size.