Style: Upper Right Upper Right Upper Left Lower Right Lower Left Advanced Series tubes are produced using the most modern metallurgy process (MIM) that allows you to gather all quality and technology requirements in a single piece. Top notch that allows better control in tube positioning. Permanent recording U (Upper) and L (Lower) indicating the correct position of each tube. Tapered wire entry that facilitates arch insertion. Clamping housing that facilitates tube positioning. Totally spherical hook that provides better comfort for the patient and excellent accommodation of the elastics.