I purchased this item from this site. Purchase price: 2500 yen Unused. This is a handmade登山用 bottle holder made using 40D ripstop nylon fabric, which is super lightweight, waterproof, water-repellent, and windproof. Foam polyethylene is used inside for insulation and to prevent deformation. It can be attached to the shoulder harness of a backpack using two magic belts and the loop at the top! It comes with a cord to attach to the bottle, preventing it from falling (see the photos). Size: Height: Approximately 16 cm Diameter: Approximately 6.5-8.5 cm Weight: 30 grams Color: Iron Gray I purchased it because it can hold a 500ml PET bottle, and it also fits a 400ml Argen bottle.