Extruded and CNC-machined from 6061-T6 aluminum BOX hub spacers feature an ultra-minimalist design that is super lightweight and extremely good looking. Weights range from 0.2 to 0.8 grams depending on the size. Sold in packs of four including two 1-millimeter and one each 3- and 5-millimeter widths the set provides hub spacing adjustments of 1 to 10 millimeters. Shimano compatible.