Cuff pivot points are a typical wear point on alpine touring ski boots. Constant motion around the pivots causes friction that can slowly erode the surrounding material. This eventually leads to some play around the pivots, which can make skiing less precise. B&D Ski Gear has come through with a solution to this problem in the form of metal-on-metal pivots that are hard enough to withstand the rigors of daily ski touring. Called Ultimate, the Cuff Pivots are designed specifically for the Dynafit TLT5 and TLT6 boots, but are also known to work on the DyNA Evo, PDG, and other boots with the same size cuff joint. More recently a version for the Vulcan was added with specifications that match that boot.
The kits come with hardware for two boots, left and right. They allow nearly friction-free ankle rotation, even less than the stock pivots. This means you’ll save a bit of energy on the uphill. There are two basic models with identical specifications, detailed below. In theory the standard model (stainless steel) is more robust but the ultralights (aluminum) seem to last forever as well. Also available are oversized bushings for heavily-worn cuffs and a spanner tool which helps with installation. For complete instructions, see the helpful post on WildSnow.