The H+Son The Hydra is an extremely lightweight 25mm-profile rim. Archetype Rim is a true V Profile Rim, with no stress points. The impeccable H+Son workmanship and our invisible welded rim joint comes standard with each rim.It is a professional and elegant rim with a sealed track hub. The perfect all around road rim. At 450 grams, this rim has proven to be light yet not sacrificing strength, stiffness, and stability.The size is 700c, meaning it is compatible with all road-bike tyres. You can mount 25 to 28 tyres and will need a 48mm-valve inner tube. And it is crucial you mount a rim strip between the tyre and the inner tube to reduce or prevent punctures.