It's puffy because it's made by layering and sandwiching batting. Size: Length 11.5cm (including the zipper) Width 13cm (at the longest part) *There may be size variations. Uses a 10cm zipper. This is a handmade item by an amateur, so it's not perfect. Please read the profile and only purchase if you understand handmade items. This product is a handmade item by *koto*yuki* using fabric from Koyan Isamchon. It is not an original Koyan Isamchon product. The copyright of the fabric illustrations belongs to JAESUNSHOP. #KoyanIsamchon