The HydraFlex: the standard red tubing that comes with most hydration packs. This is a light and simple option.

These super flexible tubes ensure a consistent flow and are very convenient and easy to use alongside the High-flow Blaster bite valve. Their valve seals automatically after each sip, so you can put it back in place and keep rolling without worrying about any drip. It also has a twist on/off feature that prevents leaks when not in use.