Rivers' bottle holder, the Bottle Harness Ivy Plus. Color: Black This is a new, unused item. The following is quoted from the web page: ■ This bottle holder can be attached to a backpack. By securing the holder at two points, the upper and lower shoulder harness of the backpack, the bottle's swaying is reduced, making it easy to use during hiking and mountain climbing. The Velcro fastener allows for length adjustment, so you can use it according to the thickness of the harness of your bag. It's also great for bicycles. Hang it from the handlebars and secure it with the Velcro fastener to create a bottle holder that doesn't dangle. You can use it in various situations, such as putting in a gas canister or a speaker. The maximum diameter of the compatible bottle is 74mm. By adjusting the length of the handle, you can adjust it to the optimal length for the height of the bottle. In addition to the conventional bottles, Rivers products can also accommodate Stout 500/700, Stout Air 550, and Stem. Rivers is a Japanese brand that focuses on "drinkware" products. They create tools that provide a comfortable experience with each use, including products for the globally popular coffee scene and outdoor activities, as well as basic bottles and mugs that are essential for everyday use. The products, which are surprisingly functional despite their minimalist design, are popular among users, especially campers and coffee geeks.