How can it be 100% polyester AND Merino wool at the same time?
This item is made from 80% polyester and 20% merino wool.
Not knowing exactly how it's made, the fabric doesn't feel like wool to me. It's very comfortable and will keep you nice and warm in as a baselayer. I'd say the material is more microfiber than anything else with a moisture wicking properties. I hope this helps.
I like it a lot and it's sleeves are perfect for a tall guy.