I would call this jacket a "wind breaker." The jacket is not lined so it is very light weight and can be worn over a t-shirt if it is rainy and warm, or easily layered with a sweatshirt for more warmth. Very versatile. It is also not bulky so it can be put in a backpack. It has a hood that is rolled up and kept inside the collar when not in use. The sleeves have Velcro on them so they can be cinched closed (no rain or wind up the sleeve).

As for size, my son wears a men's medium shirt so I bought the jacket in a large so he can wear a hooded sweatshirt under it with plenty of room. A medium would have also worked but he is still growing.

This is the second one of these that I have purchased as the first one was stolen from my son's locker at school. Considering how great the jacket is, I am disappointed but not surprised. Highly recommended for high schoolers, hikers/campers, and people who live in rainy warmer climates.

Well the jacket seems to be alright. It's too old fashioned. Not waterproof as well.