Abstract: Apparatus and methods relate to gas regulators for use with paintball guns. The gas regulator includes a poppet housing interchangeable by a user to modify output pressure of the gas regulator. The poppet housing includes markings visible externally on the gas regulator indicating to the user the output pressure provided. The gas regulator may further include a rotatable adapter for coupling with a paintball gun. A regulator piston that functions to control the output pressure based on the poppet housing selected acts in some embodiments on an internal balanced piston for selectively opening and closing flow through the gas regulator.