Agrowtek's GC-ProXL-E controls up to three climate zones and two nutrient reservoirs. Same great features as GC-Pro, with expanded hardware to handle more sensors and relays. Includes four sensor ports, eight discrete inputs, sixteen outputs for relays and one basic climate sensor. Serial & Ethernet ports for free remote monitoring software. Up to three (3) climate zones, two (2) zones each with hydroponics dosing for up to eight (8) parts plus two (2) pH.