They have been my favorite sandal but with some drawbacks. I am considering returning them. No arch gap. They work, but are a bit too small. For its price, its sadly made out of what it feels like cheap plastic and might break on your first drop. This said, I basically pushed the tubes in unscrewed, and, in the companys favor, the larger holes for the tubes are well drilled and the tubes fit snuggly w/o the screws. Luckily they work perfectly and required next to no effort to connect. Included in the box was the riser and a quick-release skewer. I would give them 10 out of 10 but 5 is the most here! This is my 2nd purchase.