BS & B Safety Systems Rupture Disk - 1 1/2" -Type: RLS-Material: Hast C-Not UsedInformation from the tag on the unit:5253-6525-54LSOC-90121-WSize: 1 1/2"Type: RLSMaterial: Hast CRupture Pressure200 PSIG @ 72 degrees F138 PSIG @ 750 degrees FThis item has not been used. The box is a little dirty from sitting on a shelf but the item is in very good condition. Shipping weight: 12 oz. (includes extra packing for extra protection)