NIKE hooded windbreaker? It's a jacket. The outside is nylon, but the inside is a warm fleece? fabric, so it's okay to wear it over a short-sleeved shirt. It's not as thick as a bench coat, and I bought it because I wanted something warm for when I use it for a marathon. Also, it's thin, light, and warm, so it's easy to wear when carrying a school bag, making it perfect for going to school. Season: Autumn Season: Autumn, Winter