CR-1 This CR1 was going to be the first hand-carved chainring using a hammer and a butter knife, but since the knife broke on the first prototype, we decided to use a CNC machine instead. It seems to have been a blessing in disguise. The CNC etched flames and the reserved FireEye hexilogo display the kind of design that FireEye is know for. The CR1 is available in both 36T and 38T configurations and compatible with both 19mm and 22mm axles through the use of the provided spacers. ................................................................................................................................................................................ Material: aluminum 6061-T6 Spildle Diameter: 23.8mm (with 22mm and 19mm spacers) Thickness: 6mm Sizes: 36t and 38t / 2.3mm (1/8") Color: black with CNC silver Surface finish: sand-blasted and anodized Logo: CNC etched