You can be the first to see my newly listed items and sales. Don't be fooled by drop shippers claiming they have these in stock. These gauges are in my possession (as are all my items). MOON Direct Mount Pressure Gauge - liquid filled.1 3/4 diameter gauge is designed to directly onto the engine, line, or? The gauge is liquid (oil) filled to eliminate needle bounce. Chrome bezel with MOON logo on the face. The gauge has a 1/8 NPT male connection.