Our M1 has expanded performance range for nearly any dive scenario, recreational or technical and is Nitrox ready up to 80%. The first stage is chrome plated brass, is environmentally sealed, and also comes with the swiveling 5 port low pressure cap and 2 high pressure ports. The M1's second stage features a surge protected front cover design, super wide exhaust deflector, and uses our engraved heat protecting jam nut for freeze prevention.