Never leave home without the essentials. The Hydro Flask Tag Along Bottle Sling - Standard holds a 12oz, 18oz, 21oz and 24oz Hydro Flask along with your credit cards, keys and other valuables. With a fully adjustable, stretch-woven Sliplok shoulder strap it can be worn across the body or over the shoulder—perfect whether you're out for a day hike, rockin' out at a music festival or setting off on a sunset stroll.