Dial 911 Headset Spacer -Dial 911 is coming in with the spacers you need to get your compression and bar height just right Pick the height extension you need with either of the options on offer. 5, 10, or 20mm spacer. Used for compatibility issues when: The Shim is too short to reach the headset The fork hits the SCS system so the compression bolt cannot be tightened Put these over your headset on the fork and create the space needed Measurements: 1. 10" (28mm) inner diameter