Silver anodized. For 39mm fork tubes. Simply installs by removing the top triple tree, or lower the forks from the triple tree, and clamp the clip-ons around the inner fork tubes. Manufactured from anodized aluminum. Comes with machined-in slots to accommodate 82-up style H-D models. Accepts regular 1" diameter handlebar controlsThis comes with approval.   Note: 517191 (silver) and 517192 (black) replacement tubes are available without machined-in slots for use on pre-1982 models. Note: Check your local MCS dealer or the MCS sales department for exact type of approval and validity on bike model and years on the test report.