Expansion Tank Gauge, Body Material Bronze, Gauge Glass Diameter 5/8 in, Gauge Glass Length 12 in, Center to Center Length 13 1/4 in, Media Temperature - Maximum 350 Degrees F, Gasket Material EPDM, Connection Type NPT, Compatible Pipe Size 1/2 in, Number of Guard Rods 2, Valve Type Needle Drain, Operating Pressure - Maximum 300 psig, Stem Packing Material Not Applicable, Standards CRN Registered