the boa system on these are rad. It does take a few runs to get them dialed though. they don't have upper and lower boa, just one. So after a run, the tension evens out and you tighten it up a bit more and then the same thing after another run. you can loosen and tighten them on the lift if you need some extra blood flow. The pump system is awesome and helps provide great pin point cushioning and heal hold. Good boots over all. True to size, size down if you expect to wear them a lot and pack them out.