300 series gauge line is a high quality line of Glycerin filled gauges. The Dry filling helps dampen the effects of pulsation and vibration, while also perpetually lubricating the movement (and keeping contaminates such as dirt away from all moving parts) which will extend the life of the gauge. This gauge has been specifically designed with original equipment manufacturers in mind. It is typically used in chemical processing or food processing applications as well as any commercial or industrial application where stainless steel components are required.