Gasco Premium Calibration Gas equivalent to MSA Part Number 476302. Gasco calibration gas is 100% compatible with MSA fixed or portable gas detectors & offers an equal mixture at significant cost savings. This calibration gas blend is 5.0% Oxygen, balance Nitrogen contained in a 17 Liter Cylinder. Gasco Gas Brand is used for bump testing, calibration & maintenance of both portable & fixed gas detectors. Bottle Connection is CGA600, Pressure is 240 PSI, contained in an Steel cylinder.