i found this tank while rabbit hunting in an old house dated 1917. it is a little rusty and has numbers on it . i think it might be co2 but not sure to me it looks like and old soda companys tank it is very heavey so im excluding divers tank . wrong valve for a welders tank . i took a close up of the valve . also these are 2 rabbits that my bluetick beagle wont be chasing antime soon . ps 1 of my plants has been flowering since the 12th of jan . nosmoke came over and wanted to sample 1 lol yea right .