Profile: The seal has a profile to it and allows for a one/two or full transform on the pressure gauges readout to make certain good installation orientation. Profile seals can both be exterior or internally centered. It is made up of a skinny versatile diaphragm made from materials for instance https://andrestjwjy.articlesblogger.com/55629584/what-does-diaphragm-oil-pressure-gauge-mean