Works perfectly with Leatt adventure neck brace. This is awesome for trails with trees and rocks due to the back support design, It goes low on your back, but not enough to cause a problem with it riding up and affecting the neck brace. I have had problems with other brands until Leatt came out with their own. We have 3 of them, the kids are used to it, and they say they don't even notice it. One kid rides with the arm pieces off. Nice feature that you can just unzip them, if that's your preference. I have one also. I am 5-9 155 lbs and I have a Large, fits perfect. Sizing charts are correct. One minor issue: I wear mine over a riding Jersey, as the neck brace, when on, does not allow for a jerseyâ€¦However my son bought an x large Jersey, and he manages to wear it under the Jersey by putting the neck brace on over the Jersey, so it can work. Just needed that extra play in the fabric of the Jersey to allow the neck brace to set down into the body armor slots.