A pony tank is a smaller tank, which is carried additionally to the mostly single main tank. It possesses its own regulator with first and second stage and sometimes a gauge too. It will be mounted either at ones side or in front of the body or fixed at the main tank. A pony bottle scuba tank is the only true redundancy you can rely on. When shipped the tanks valves will be removed and the tank will require re-inspection before being filled. All Catalina cylinders are Nitrox Ready!
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