It is used in high pressure Boilers, HP Heaters, Turbines, Pressure Vessels, Reactors for direct water/liquid level indicators. It can withstand up to 3000 PSI pressure and 400 Deg. C temp. each kit consist of Round Gauge Glass, Clear and Transparent Mica discs, Metallic Sealing Gasket, Clip-Ring and Cushion Gasket.