This adapter allows you to raise your existing ahead stem or fit an ahead style stem to a bike with an old style quill stem. It extends your steering tube without affecting the ahead system. The adapter is compatible with both threaded and threadless headsets and is made from machined 6061 aluminum. It features a 25.4mm upper diameter for stem mounting and a 22.2mm lower diameter that bolts inside the existing steerer. The stem spacer length is 85mm, and it fits a 1" steerer tube. A sandblasted black BBB RoundHead top cap is included. This adapter is designed for 1" forks.