Professional's Choice Equisential Twisted Wire D Ring Bit Made of sweet iron with copper inlays to keep the horse's mouth soft and moist. This bit works well for green or sensitive horses. 3" rings and 5 1/4" mouth. NOTE: This bit will rust when exposed to moisture. This creates a sweet tasted in the horse's mouth and promotes salivation. Features: Copper inlays Item Specifications: Size: 3" Rings, 5 1/4" Mouth