Texas Remcor Chemical Isolator with Mounting Bracket 1/4" FNPT - ISO.2391 The Chemical Isolator prevents chemicals from entering the tractor cab, enhancing operator safety and extending the life of gauges and monitors. It cushions and shields pressure gauges from corrosive substances, while its large-capacity design ensures precise pressure readings. Rated for a maximum operating pressure of 150 PSI, the unit comes pre-filled at the factory with non-toxic RV antifreeze.