The carbon tubular Smart ENVE System 3.4 wheelset consists of a 35mm deep front wheel paired with a 45mm rear wheel, fitted out with Chris King hubs (Shimano/SRAM compatible) and 20/24 front/rear spokes. They claim to have created an all-round wheelset that is equally at home climbing hills in races or sportives as it is in a flat time trial, in any weather. It's also an alternative to the deeper sectioned 6.7 wheelset in blustery conditions. And with a combined 1,243g weight, they're certainly light.
As with the 6.7, the front wheel at 26mm wide and 35mm deep, is wider and shallower than the rear (24mm wide/45mm deep), which is said to have the effect of reducing drag and improving stability.