Our best-selling bra with a comfortable and lightly supportive fit, the Siren Bra features our 150gm jersey corespun fabric, which uses merino wool fibers wrapped around a nylon core for added strength and durability, while retaining next-to-skin softness. We've added a touch of LYCRA® for active stretch. The Siren’s sleek design and no-side-seam construction is perfect for everyday comfort and easy layering, while its thin adjustable elastic straps make for a barely-there feel. Featuring a slim, modern fit and our corespun merino wool fabric for durable comfort, the Siren Bra offers the support you need with a soft, sleek and stretchy construction. Merino Corespun - merino blend regulates body temperature in all weather conditions Flatlock seams to help reduce friction Low support Adjustable straps Removable Cups