Rab's AL Pull-On Men's Layer is a lightweight fleece that can be worn next to the skin or as a light midlayer on colder expeditions. Either way, the Polartec Power Dry fleece will provide lightweight insulation and breathability, while its slim fit makes it easy to layer up when the going gets really cold. Best of all, Rab treated the it with Polygiene, an antimicrobial treatment that fights off stink so you can spend days in the mountains without smelling like a yeti's feet.