FREE SHIPPING IN THE USA The addition of the Hose Barb now allows the unit to be used while checking air quality at the tank or while the user is connected to their first stage regulator (via their BCD's low pressure inflator). The newly designed packaging and colour theme has been created to give this iconic product a polished finish, making this product not only the most reliable nitrox analyser on the market but the best looking one too. The O2EII Pro is a highly accurate device and a must have for any scuba diver, the unit comes with a 3 year graded sensor warranty and has an expected sensor life of 4 to 5 years in air.