This is a combination pressure/vacuum gauge with a 1/4 inch bottom mount, 2-1/2 inch face and stainless steel case. This swimming pool pressure gauge is designed to read from negative 30 to 30 PSI. It is liquid filled for a more accurate reading. The case is stainless steel and painted black. It has a glass lens with all brass internals.
A swimming pool pressure gauge displays the exact pounds per inch (PSI) of your pool filter, which requires some pressure inside its tank to operate. When the filter pressure is normal, water is flowing through it fairly seamlessly and your equipment is operating smoothly and safely.