Attaches to filters with a 28 mm thread, such as the Sawyer Squeeze, Mini, or Micro, the LifeStraw Flex, and the HydroBlu VersaFlow One liter capacity bottle with a slim profile that fits easily into backpack side pockets and shoulder strap pockets alike. Ounce and milliliter measurement lines Tethered cap Nylon string near the cap for easy pull from side pockets The ThruBottle is the result of multiple years of design, testing, and refinement. The final product is a patent-pending, one liter bottle that’s lightweight, slim, and safe to use over the course of a long hike. Designed with ultralight backpackers in mind, it's constructed from safe, durable materials intended for long-term use - even through long periods of sun exposure and rough conditions.