2 1/2in. diameter gauge. Stainless steel case. Glycerin filed to handle more vibration. 1/4in. MNPT brass stem. Bronze tube. Aluminum dial face. Center back U-clamp mount is cadmium-plated steel. Grade B. All are designed for use with air, gas, oil and water. Hole for mounting must be 2.475" or larger but less 2.6" in size U.S.A. Compares to current or past OEM associations: Mytee H308D Pumptec LFG-PM-2000 Pumptec 31288 Karcher 8.712-135.0 Prochem 8.710-257.0 Blue Baron AR3223B Used on EDIC Endeavor 9000i series Northern Tool 53616 Sandia Plastic 80-0059-4