Tyvek fanny pack iphone waist bag phone case made of DuPont Tyvek Paper which is a durable and eco-friendly paper-like synthetic material. Tyvek shares many properties with paper - it's thin, lightweight, foldable and it even wrinkles, giving it a unique and personal character. Unlike paper, Tyvek is waterproof, breathable and super-strong, making it a durable and versatile material.