Vest with pocket for body warmers. Sizes are LL to 3L, but recommended for men's M or women's L size. This is a personal opinion, so please check the measurements before purchasing. No returns. Longer back to keep your lower back warm. Light and comfortable. Warm as an inner layer. No need to peel off body warmers from your clothes. Applying to the lower back prevents lower back pain. Applying to the shoulders is good for stiff shoulders and back pain. Three body warmers will eliminate the need for heating. Can also be used as an outer layer.