"The clincher version of the 404 utilizes the same go-anywhere, win-anything 58mm rim depth of the tubular model but offers the everyday convenience of clincher tires and the reliability of an aluminum brake track.
For greater strength and reliability, Zipp's M2CM technology fuses the aluminum hoop to the inner carbon section during the molding process. Still, the 404 clincher’s 1658g total weight is less than many full-carbon clinchers. Of course, none of those other wheels offer Zipp’s exclusive features like ABLC dimples, VCLC vibration-reduction technologies, and the smooth, stiff, durable 88/188 hubset."