The Icebreaker Men's Tech T Lite SS is a hiking shirt for staying cool in the summer sun. The 150gm ultralight material is 100% merino wool, which Uses its natural wicking abilities to regulate your temperature. Wear the same one day after day, it's odor resistant means no stink. The light weight also make it packable, so throw in an extra to your stuff sack just in case. Quick drying, so hang it overnight and you're good to go by morning. I hope it doesn't rain. Features of the Icebreaker Men's Tech T Lite Short Sleeve Ultra lightweight A touch of Lycra for a great Fit Naturally odor-resistant Breathable Crewe neck Set-in sleeves