Gear Review: Mammut Zip Longsleeve All-Year Baselayer

Using body-mapping and blended merino wool/synthetic fabrics, this innovative baselayer is warm and versatile.

Most Innovative

This shirt takes two smart ideas–blended merino wool/synthetic fabrics and body-mapping–and puts them together in one hardworking layer. The hybrid fabric provides a touch of extra warmth in key areas that tend to lose heat rapidly, while the all-poly panels enhance wicking in high-sweat areas.

The combination makes it warm for the weight, yet still highly versatile. Add an athletic fit, tall neck, and long sleeves, and one veteran tester concluded, "This is my favorite baselayer now–and maybe ever." $80; 7 oz.; men's S-XXL; mammut.ch.