tysonhwrote a review of Outdoor Research Sun Runner Cap on July 6, 2018
Familiarity: I've used it once or twice and have initial impressions
Excellent cap all around. First one I've ever bought like this, but I like it. Plan on using it for extended backpacking trips when it gets hot. Pay attention to the size chart though. Backcountry didn't have a size chart that I could see for this cap, and so I guessed a medium would work for me. I was wrong, as it's way too small. But I like it and so I'm going to keep it for my kids to use, and then pick me up another one. Here is the size chart that I found on another website:
Small 21-5/8 in.
Medium 22-1/2 in.
Large 23-1/4 in.
X Large 24 in.