Icebreaker Size Chart A soft and stretchy women's T-shirt with an updated fit and fabric that makes it even more comfortable, the Siren Long Sleeve Sweetheart is made with Icebreaker's corespun fabric, soft merino wool fibers wrapped around a nylon core for added strength and durability, while retaining next-to-skin softness. Ideal for year-round use whether traveling, hiking, or relaxing after a big day outside, the Siren Long Sleeve Sweetheart also features a flattering neckline and a fit that's perfect for everyday comfort and layering. Features: - Corespun fabric for enhanced durability - LYCRA(R) content for stretch and mobility - Soft v-neck - Icebreaker tonal screen print logo - Fabric Weight: 150 Ultralight - Fabric: 83% Merino Wool, 12% Nylon, 5% LYCRA(R) - Product Weight: Medium = 196 g / 6.91 oz