Box Two Headset Adapters allow the use of 1-inch threadless headsets and forks with 1-inch steerer tubes in frames designed for standard, 1 1/8-inch threadless headsets Box Two Headset Adapters allow the use of 1-inch threadless headsets and forks with 1-inch steerer tubes in frames designed for standard, 1 1/8-inch threadless headsets Please note, this adapter is not designed to be used with integrated headsets.