Color: SilverThese board rack mounts are machined from aerospace-grade billet aluminum and are anodized and electropolished to give you years of maintenance-free use. Designed specifically to mount the PTM Edge CBR-100 and CBR-200 Clamping Board Racks or the PTM Edge BBR-100 Bungee Board Racks to a 1.9��_-diameter pipe tower.