Published by at 04/08/2026 The Arc'teryx Women's Phase AR Base Layer is a versatile and stylish activewear top perfect for outdoor activities and casual wear. Featuring a solid black color with a mock neck and long sleeves, this pullover has a 1/4 zip closure for added versatility. Made from a blend of polyester and polypropylene, this lightweight and breathable top is designed for comfort and performance. Ideal for walking, hiking, running, and jogging, the Phase Base Layer is easy to care for and quick to dry, making it a practical choice for all seasons.