base layer from the merino xtreme collection . the thermowave base layer top is soft and with 220 gsm a base layer for the colder days of the year. the composition of merino wool, polyamide and a polyester lining ensures plenty of warmth and best breathability while you enjoy all the benefits of merino wool. fast moisture-wicking and odour inhibition are of course the top priorities here. flat seams also provide plenty of comfort, while the longer cut at the back ensures perfect coverage.