Includes Red Sea Reactor 500, CO2 Regulator, high precision in-line Needle Valve, Bubble Counter with integrated check valve, real time CO2 monitor, and 3 meters of CO2 tubing, Red Sea is pleased to introduce an exciting new CO2 system for planted aquariums, The Pro System is a complete, efficient and user-friendly system to maintain a desired level of CO2 in planted aquariums from 10 to 125 gallons (40 to 500 Liters), SKU: RYLHC4663