Michaelsoft_wrote a review of Backcountry Topo Merino Comp Trail Sock on December 29, 2015
These are some of my go to socks. I wear these with boots from fall to spring. The upper is thin so it doesn't add a ton of bulk. I sized down to s/m for a size 8.5-9 sized foot. I enjoy them tighter than looser but I think medium or small would suffice.