The Box One Race Stem Lock keeps your setup together if you're riding hard enough to break your steerer tube. Cold forged and fully CNC-machined from several high-strength aluminum alloys, new Box One Stem Lock offer peace of mind and a level of added protection against losing your front wheel and fork legs in the event of a broken steerer tube. All new Box One Stem Locks are backward compatible with existing Box forks and may work with forks from other manufacturers. Colour: Red, Black, Blue, Silver; Size: 1", 1.5", 1-1.5", 1-1/8", 1-1.8"