Size medium but would fit size small really nicely. The Montbell Down Filled Hiking Jacket is a stylish and practical puffer jacket designed for outdoor activities, specifically for hiking in the winter season. Made with a durable nylon outer shell and insulated with warm down filling, this grey jacket provides excellent warmth and protection against the cold weather. The regular fit and size M make it suitable for casual occasions, while the nylon lining adds comfort and breathability. With the renowned brand Montbell known for quality and performance in outdoor gear, this jacket is a reliable choice for those looking for a versatile and functional winter jacket.