All parts of your layering system should perform well in demanding environments. The Black Diamond Women's Compound Hooded Fleece Jacket fill the niche as a high-performing midlayer, that is not only breathable during the ascent, but thermally efficient when you're at rest. Made with Polartec Power Stretch Pro fabric, the Compound Hoodie is highly breathable and has plenty of stretch to remain comfortable during technical alpine routes. The low-profile hood fits comfortably under a helmet, and the stretch cuffs have thumbholes to keep the sleeves secure under your shell jacket. The two hand pockets are concealed to minimize bulk and yield a more streamlined fit that works well the jacket's more contoured, technical fit.