Aero efficiency quick acceleration and the improved ride quality of UST Tubeless. You get it all with this carbon road wheel featuring easier to use Road Tubeless technology and a lighter weight. This versatile carbon road wheel is ideal for riders seeking the perfect balance between weight aerodynamics and efficiency. New spokes and hubs give the Cosmic SL 40 a light and lively feel for climbing and accelerating. Accelerate and climb faster hold higher speeds 40mm NACA inspired rim shape minimizes drag for added speed Reduced inertia of the lightweight rim delivers instant acceleration Flat double butted spokes saves weight and improves responsiveness Versatile performance for all road riding conditions Minimal drag low inertia and high lateral stiffness makes it fast and efficient on all types of terrain from the flats to mountain climbs iTgMAX brake track offers the best braking efficiency and highest reliability of all carbon rims Improved UST Road delivering speed comfort and control No tubes means less friction improved efficiency and grip with reduced risk of punctures Rim bed shape makes it easier to mount and change tyres Weight Pair: 1600g Rear: 895g Front: 705g Understanding the different Mavic freehub body acronyms: HG or M11 – Shimano HG Road 11/12x other speeds with spacer MS - Shimano Microspline XD - SRAM XD XD-R - SRAM XD-R ED11 - Campagnolo 9/12x N3W - Campagnolo 13x