How do we know what size we need? What...
How do we know what size we need? What do we measure to find out and where? We are interested in gaiters for a gorilla trek in Rwanda and only need them to go up to our mid-calves or so.
For that kind of activity you will probably want to looks more at a mid gaiter like the Rab Latok Mid Gaiter or the OR Flex Tex. These well keep debris and light moisture out of your boots and lower legs while being more breathable and not as intense as a full size alpine inspired gaiter.