One is new, and one is a used bonus item. It has a moderate thickness and is just right for regulating body temperature. I also bought a size 150 and liked it so much that I bought it again when I needed a size 160. I bought greedily and one is still new, unused because I outgrew it. It's a recommended item. The used one has no noticeable flaws, but it shows signs of wear. If you don't need it, please let me know after purchase. [Measurements (amateur)] <New> Length: Approx. 57.5 cm Body length: Approx. 60 cm Width (underarms): Approx. 46 cm <Used> Length: Approx. 60 cm Body length: Approx. 61 cm Width (underarms): Approx. 46 cm (It seems to have stretched or shrunk with washing, but the difference in size is not significant.) It gives the impression of a slightly relaxed fit. Please feel free to ask any questions. (^o)／ #Vest #Waistcoat #Innerwear #Body temperature regulation #160 #155 #Boy #Male #Boys #Kids #Cotton #Cotton #B #BEAT #BKIDS #BEAKIDS #Cardigan #Green #Green #Dark green