About as solid as it gets for a pure merino tee - Mountain Hardwear Diamond Peak Short Sleeve T-Shirt - Men's

For temperature/moisture/odor management, you really can't beat 100% merino wool. Durability can take a hit if that's the case, but with this tee, I've been pleased by how well it has held up. If you take some care when washing and drying the shirt, it will last.

I've taken this tee one shorter trip, as well as using it for multiple days through climbing/training without a wash and it does exactly as advertised. This stays the freshest, the longest of any shirt I own. It's super soft with no itchiness at all. The fit is a little bit trim, but still relaxed and what I would call slim. I'm sometimes between M and L and glad I stuck with the Large.

At a discount and possibly even full-price, this is definitely a worthwhile buy. Recommended for a base layer, bike commuting, workouts and traveling, but really this thing is great for anything.