The Castelli Merino Long Sleeve T-Shirt is designed to be worn as a technical base layer or a casual top.The fine-gauge merino wool knit incorporates polyester for strength and ease of care, but retains the naturally odourless, warming and high wicking properties of merino for a luxurious feel whether you’re wearing it under a cycling jacket or recovering post-ride. Key Features: Designed for casual use or as a performance base layer,Fine-gauge merino wool knit with polyester for strength and ease of care,Shaped collar,Button logo and woven label,Slim fit,.