Marina Air Control Valve. The Marina Ultra 2-way air control valve allows you to run up to 2 air-driven devices at once. Each valve has a flow adjuster which enables you to regulate air output to each devise. The Marina Ultra 3-way air control valve allows you to run up to 3 air-driven products at once. Each valve has a flow adjuster which enables you to regulate air output to each devise. The Marina Ultra 4-way air control valve allows you to run up to 4 air-driven products at once. Each valve has a flow adjuster which enables you to regulate air output to each devise. The valve is leak-proof and suitable for fresh or saltwater aquariums. The valve can easily be hung on all standard aquariums.