This is a set of 4 small MUJI hot water bottles and covers. You can use two each to warm your feet and abdomen. Although small, they stay warm until morning. The covers feel great to the touch. The zipper is also covered, so you can use it softly without metal touching you. I bought these for guests and used them once. The covers have been washed with organic detergent. I purchased these a year ago, and the cover design is different from the current product. The hand-stitched style warms the heart. Retail price: Cover: 790 yen Body: 790 yen Total for 4 sets: 6,320 yen [Body] Country of origin/region: Japan Material: Body: Polyethylene, Cap: Polypropylene External dimensions: Approximately 6.5 x 23 x 17 cm Capacity: 1.2L [Covers] Moss green, Navy Body: Polyethylene, Cap: Polypropylene Composition: Outer fabric: Pile: 100% polyester, Base fabric: 100% polyester, Filling: 100% polyester, Lining: 100% polyester