extra warm merino base layer . the thermowave base layer top is soft and with 265 gsm a base layer for the colder days of the year. the composition of merino wool and elastane ensures plenty of freedom of movement 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.