As a part of Devold's lightest Ultra Light lineup, Breeze base layers are highly comfortable and versatile. Pure Merino wool is comfortable even when frequent washing is not possible - the material requires less washes than technical ones. - Naturally odour resistant - Made of 100% Merino wool - Super fine fiber (17.5 miron) - Machine washable (use wool detergent and wool cycle) Devold undergarments are treated with a natural compound made to protect the apparel from wool-eating insects. It has a gentle, citronella-style scent and is completely harmless to people. The treatment protects the garment for one year and its scent diminishes and fades away with airing the garment.