The low profile hook and small ball are milled from a single piece of metal for increased patient comfort 3M offers an innovative color coding system that assigns a different color to each quadrant of the mouth for immediate identification Gingivally Off-Set Bicuspid Bracket features a three point contact design along with rounded corners for a great base-to-tooth fit Specifications Adhesive Precoat: APC™ II Prescription: Samson* Slot Size (Imperial): 0.022 in