Neptune Systems A3 Apex Pro Aquarium Controller System -- The most complete experience of monitoring and control for the discerning aquarist. Fully equipped A3 Apex Pro base unit with features including WiFi and Ethernet compatibility, 4 FMM Ports, and an Energy Bar 832. Designed to monitor key parameters like temperature, ORP, and pH with included lab-grade probes. Includes a new Liquid Level Sensor and Optical Multi-Surface Leak Detection Sensor. Suitable for both saltwater and freshwater aquariums.