Thank you for viewing. This is a ZETT wind layer shirt. It's worn over an undershirt and blocks the wind. It can also be used to promote sweating. The back of the collar is made of stretch material. There is a snag in the thread near the right sleeve. Please refer to the third photo. Part of the ZETT print mark is peeling off. Please refer to the fourth photo. It can still be worn! It has been worn and stored at home, so please understand this. It will be folded compactly for shipping, so there may be some creases.