Leather Jacket Women's L fits M

Bought this jacket at a fancy store in Argentina called Las Pepas. This is a pure leather jacket made by the brand. Needs a new zipper and some sewing to the inside fabric. The leather is in good condition and will last years, because of its great quality. Has a pocket on the inside. I wore this jacket for years and it just does not fit me anymore. It's L but fits M great. Sizes in Argentina run smaller than in the US.