The Yonder Tether Cap attaches to the existing chug spout and stays connected to your bottle. The ultra-durable screw cap and tether mean you have less to lose out in the wild, and more to drink. Whether you're backpacking, climbing, or just out in the sun, the Yonder Tether Cap will keep you hydrated and your bottle secure. Do not use this Yonder Cap with hot, or carbonated beverages or use as storage for food or perishables.