The Yellow Jacket Omni digital vacuum gauge is an easy-to-use, compact vacuum gauge that is loaded with features for the price. And it's rugged, too. Made with high impact, glass reinforced housing, it survives moisture and accidental drops or attachment to a high pressure line. The easy-to-clean vacuum sensor handles 450 psi positive pressure and reads several units of vacuum (microns, milli-bar, Torr, and Pascal). made in United States. Manufactured by Ritchie engineering Co.