Thank you for viewing! This is a duck-patterned water bottle cover. The inside uses a thermal insulation sheet, so it can be used all year round. It has a D-ring on the side, so you can attach your own strap, etc., and use it. My elementary school child doesn't need a large water bottle in the winter, so they attach the shoulder strap from their 1L water bottle (used in the summer) to this cover and takes a smaller water bottle to school. This listing is for the cover only. Size: Height: 21cm Width: 12cm (when laid flat) Gusset: 6cm x 6cm With stopper The water bottle in the photo is 600ml. This is a handmade item. While I make them carefully, please understand that there may be some slight imperfections, such as warping or misalignment, before purchasing. If you are looking for a perfect product like a mass-produced item, please refrain from purchasing. Thank you very much.