Most of theirs have a "chamois guide" that makes claims of how long they are comfortable to ride in. How they determine this and how consistent it is with the consumers, I have no idea, especially since saddle model and saddle tilt also play a factor. Also note that their price points don't always align with their chamois levels. I recently bought a pair of Evo 2.0 bibs with their "E6 carbon" chamois rated for 6+ hours, but haven't had the chance to test that claim yet.