Product name: Helmet Lining Hat Product size: 25.5*18cm/10*7.1in Cap circumference: 52-56cm/20.5*22in Product material: polyester Product features: 1. Cold-proof cycling cap suitable for outdoor activities, skiing, mountain climbing, and more. 2. Features a soft lining for warmth and comfort during cold weather. 3. Designed to fit snugly under a helmet for added protection. 4. Made of high-quality elastic materials for warmth, comfort, and flexibility. 5. Provides excellent insulation and comfort, making it ideal for various outdoor sports activities. Precautions: 1. As we all know , the different computers display colors differently, the color of the actual item may vary slightly from the following images. 2. If you feel difficult to choose the size, you can feel free to contact me we will give you some suggestion, but it is for you reference only. Package includes: 1 pc Helmet Lining Hat