Arc'teryx Men's Ionia Merino Wool Short Sleeve T Shirt Void DADOS COM ATIVIDADES PARA JOGOS E BRINCADEIRAS ~ Atividades Escolares. A high performing merino wool t shirt from Arcteryx, the prime merino fibres are wrapped around a nylon core for increased durability. Designed to regulate your temperature, with plenty of stretch and a silky handle which is good for all day and longer wear in tough conditions. Subtle branding to the chest.