Flat discs are soooo 1980s. Actually, they were the most aero wheels available all the way up to 2007. For 2008, HED integrated the patented toroidal rim into a flat disc and achieved a new level of aerodynamic savings. The Jet Disc combines amazing drag characteristics and low rolling resistance due to the clincher rim. The Jet Disc may be the fastest TT wheel out there and will be available this spring for $1,000