Was looking for something to wear on long skins that would breathe and not absorb moisture causing me to freeze at the top. Previously tried fleece vest, micro-puff vest, and ex-weight fleece top. No va. The HH Barrier jacket is it. Super spartan - only one pocket, very light and thin - barely more substantial than a light shell. The hood is a bonus, tho. Works perfectly over a midweight top to keep the sweat moving as long as it's exposed to the air. Not only did it keep me warm on the climb, I zipped 'er up and skied cold, north-facing slopes without a hint of cold getting through the dense fabric. So far haven't used it in wet conditions.