I use OMS steel low pressure 85’s. The tanks have 85 cu. ft. when filled to 2450 psi. You get a better fill because the tanks don’t get so hot. Also when filled to 3200psi the tank now has just over 100 cu. ft and your not charged for a HP fill. The tank bouancy also doesn’t change at all from filled to 500 psi. In Europe these same tanks are rated as high pressure. The DOT only allows a 2450 psi in the US. Great way to get 103 cu. ft. for a LP fill cost and also easier on the dive shop to top off.