The Apex Controllers from Neptune Systems are modular systems that allow you to connect many modules together in either a daisy-chain or star topology method. Use this cable to connect the Apex controller, modules, and Energy Bars together. Please Note: AquaBus Cables are USB-type cables but Apex Systems does not have a USB interface. DO NOT plug into any computer or other USB device – severe damage may occur to your Apex or the device you connect.