This shelled retro-x pullover is amazing. It is so warm, and comfortable. The dual material is ideal for the outdoors, making it easy to clean. In Patagonia I am between sizes small and medium. I am 5’3” 115 lbs. I went with the medium after reading the reviews saying it was hard to get off, I did not have a problem getting it off but I can see if I went with a small it may have been more difficult. The medium is perfect for layering underneath. I went on a road trip with my husband in our convertible in Northern Michigan, it was cold in some spots but my Patagonia pullover over a sweatshirt was perfect. It was a splurge but well spent. Glad I got it.