A form of gas used in the sport of paintball to propel paintballs from a marker. Nitrogen (or N2 for short) can be stored in Nitrogen or High Pressured Air tanks alike since both can hold very high pressures of gas. While N2 can be stored in HPA and N2 tanks, it cannot be stored in CO2 tanks due to the very high pressures of Nitrogen required to shoot which a CO2 tank simply cannot hold. Many high end guns require HPA or N2 to shoot.