The Hydro Flask Wide Mouth Flex Cap is the ideal combination of strength and flexibility. Designed for ultimate portability, we crafted every detail with easy-carry comfort in mind and insulated it too, so you can go further, for longer, keeping your favourite beverage comfortably by your side. Compatible with all Hydro Flask Wide Mouth Water Bottles, the Hydro Flask Wide Mouth Flex Cap features Honeycomb insulation to help keep cold drinks cold and hot drinks hot. Whether you’re out in nature or stuck in the office, it’s always a good idea to have an extra lid for your Hydro Flask. Maintain the temperature of your contents longer, so you can stay busy and get more done. This Hydro Flask product is backed by a manufacturer's lifetime warranty.