The Hydro Flask 24oz Lightweight Wide Mouth Trail Series Bottle is designed to offer superior insulation without the extra bulk when weight matters. Thinner stainless steel walls and a perforated strap that is attached using aluminum pivots make this bottle lighter than traditional Hydro Flask bottles. The slim design of this bottle allows it to fit in most cup holders and is compatible with many backpack hydration filters. It includes a twist-off wide mouth lid that makes it leakproof when closed.