These arm warmers are engineered with the arm and elbow in mind. Joints move, so these move where they need to, and stay put where they need to stay put. All so you can run free and warm. Features: - PhD(R): Built for Performance in the Highest Degree - Seamless construction for warmth with maximum freedom of movement - Non-binding welts at wrist and bicep openings keep warmers in place - Knit in USA of Imported Yarn: 61% Merino Wool, 36% Nylon, 3% Elastane - Last Chance: Discontinued Style