The SLR 2 42 WheelSystems are lightweight and robust carbon wheels that are built to last. Combining hookless rim design and optimized carbon layup with a modern, 19.4mm inner width, the SLR 2 42 & SLR 2 42 Disc deliver great value to performance cyclists who require minimal tradeoff between price, weight, and durability. - Hookless rim design enhances overall durability and offers a wider inner rim width without adding weight - Optimized carbon layup features high tensile strength carbon fiber placed at the most crucial points to provide stiff and lightweight wheels - 42mm deep all-round rim profile with a 19.4mm inner width offers better support for today's higher volume road tires - Giant's proprietary High Glass Transition Temperature (Tg) resin enhances the rim's overall durability and braking performance