Thre are a number if CO2 bags out there, you have the bags (CO2 Bags) Aresol cans, Pads (green pads), and boxes ( ther are two specific one's one for veg and one for flower. Know that the best CO2 are tanks - but for small spaces the other work some what - Do know that the Temps' has to be about 80 degrees for the bags, boxes to work properly What is you take? a waste of money?