The Apeks XL4 Octo is a yellow alternate air source version of the XL 4.  Compact and cold water rated it's the perfect accompaniment to the XL4 regulator. 

• Compact and lightweight 2^nd stage improves comfort and helps reduce jaw fatigue on long duration dives.
• High performance pneumatically balanced lever operated poppet valve.
• Large, over molded self-flushing and controllable purge button.
• Ergonomic Venturi lever is easy to use and locate.
• Yellow flexible nylon braided hose has better cold water performance than traditional rubber hose.
• Standard metallic hose connection for interchangeability.
• Comfo-bite mouthpiece has a unique bridge that fits across the upper palate and does not require bite pressure to stay in place.
• Re-usable mouthpiece clip makes it simple to change mouthpieces in the field.
• Durable and flexible rubber exhaust tee provides excellent bubble diversion.
• UV inhibitors to help prevent discoloration of the materials.