The Icebreaker Women's Siren Cami is a 150 weight Merino wool cami with Lycra added for stretch. This is a great yoga top. It fits close to the body and Merino not only feels GREAT on your skin, it dries fast and won't smell like a polyester cami. The Women's Siren Cami features adjustable elastic straps and a unique printed design. You'll love it.