Since the early eighties, the Dura-Cage has been one of the lightest and most durable bottle cages in the world. Made of 2017 Duralumin - exclusive to Minoura, these cages are as tough as they are light. This material is somewhat unique to the cycling world, but has been used for many years in the aircraft industry. The reason is simple. It is a material that is incredible light vs. its weight. Beyond that it lends itself perfectly to be manipulated and shaped without losing any of its strength. What you get is a 38 gram cage that is incredibly inexpensive. If you want a cage with the weight of carbon and about 1/4 of the price, the Dura-Cage is a great choiceThe svelte 4.5 mm diameter alloy tubes fit all bottles and reduces weight while remaining durable. The finish of the cages are anodized for added durability and longevity. The cage is supplied with two 12mm mounting bolts that are constructed from Duralumin as well.