The Grainger website features sight glass liquid level gauges, which are used to visually indicate liquid levels in tanks or vessels. These gauges allow operators to monitor liquid levels and detect problems. They consist of a chamber with transparent glass or plastic windows mounted on the tank. As liquid rises or falls in the tank, it becomes visible in the gauge. Models are available in metal or plastic in various sizes and pressure ratings. Common applications include water tanks, chemical processing, food & beverage, pharmaceuticals, and more. These simple devices provide a reliable way to monitor liquid levels at a glance.