The Patagonia Performance Baselayer Thermal Set is a men's top in size medium and bottoms in size large, perfect for outdoor activities in the winter, fall, or spring. Made of lightweight polyester knit fabric, this set features a mock neck with a pullover and zip closure, along with long sleeves and a stand-up collar. The black color and solid pattern make it versatile for various occasions including travel, activewear, casual, and business. With moisture-wicking and quick-dry features, this set is ideal for walking, school, or golf, providing mild compression for comfort and performance.