Perfect size to travel with, it?s about the size of my phone. If youre really look for a good book about Dr. I have not tested them so I cannot speak on them. Nice fit and good heal height for me. Easy to install and remove, holds bikes securely. They are going with me on a trip to Las Vegas later this year & hopefully I can walk comfortably in them for an extended period. I also liked how the construction of heavy gauge steel was carried over from the earlier versions and the springs, nuts and bolts are all very heavy duty that are meant for daily shop use for years of wheel truing. Use 2 sheet rock anchors, screws and washers to mount each tire support. I keep it folded in the garage when not in use. No dice--they poke through anyway.