Ocean Reef Neptune III 2nd Stage RegulatorNeptune III 2nd Stage Regulator It is a kit that includes a fully pre assembled Neptune III regulator. OCEAN REEF Neptune III IDM customers can enjoy the flexibility and possibility of a back up regulator. Ideal for dive teams (i. e. public safety, military, intensive use divers..). The Neptune III swap regulator must be purchased and installed through an OCEAN REEF Authorized Service Center, or OCEAN REEF Authorized dealer with Level 1 Service