2" Oil Filled Vacuum Pressure Gauge - Stainless Steel Case, Brass, 1/4" NPT Lower Mount, 30 inHg/30 PSI - Ideal for HVAC, Hydraulic Systems & Industrial Applications

This gauge works perfectly, and is much better than the air filled version. If you're wondering whether you should spend the extra money for oil filled, trust me and go for it!! I had an air filled unit, and had constant issues with it, it actually had a slow leak that I was never able to fix. In addition to which it had a plastic face, this one is glass, and it just feels more substantial and better built overall.I'm sure the air filled one was fairly accurate, but this thing really gives me the peace of mind to know exactly what the vac pressure is inside my chamber. No more needing to flick it to get a reading!Super easy to install, use and read, even if you've never done it before. Just don't forget to use either thread tape or pipe dope and keep it only on the threads, don't get any on or in the small hole in the bottom of it.