These look gay as fuck by themselves but they're both really warm and breath really well. Scandi thing. The mesh forms air pockets under the stuff you wear over it. Can get them in wool (pictured) or synthetic. They're almost too warm for where I live.
This particular product is Aclima's "woolnet."
>>1924176>You've been doing it for years. Why?You can choose not believe me if you want to but years ago around this time of year, not long after /out/ was established as a board, I posted a thread asking about longjohns. I googled "longjohns" and selected the first picture that come up without really looking at it - the one in the OP. It attracted some attention and lots of gay shitposting for the first 30-50 posts or so until people actually talking about the topic at hand and not their bulges. Haven't posted one since. Other anon(s) seem to have taken up the torch and turned it into a running gag complete with the customary new thread title.