JOES Economy Tire Pressure Gauge, 0-30 PSIJOES Economy tire pressure gauges utilize a Bourdon Tube design that includes a metal pressure tube along with a small gear rack. This is a delicate but accurate mechanism that is sensitive to shock, over pressurization and vibration. It is best for garage use. This gauge head technology is inexpensive and is very common in the vast majority of entry level gauges on the market today. While this is the most affordable gauge we offer, the Bourdon tube