SSI TechnologiesMG-9V Series, MG-30-A-9V-R - 9V Battery Operated Digital Pressure Gauge, 30PSIG, 2.5” Dial with LCD Display and ABS Case, 0.50% Accuracy, 1/4“ NPT Male Stainless Steel Connection

I needed an accurate gauge for determining water pressure, and this is by far the best one I've ever used. It's so sensitive that the reading will change as you walk up or down stairs with it turned on. Calibration is very simple and takes 5 seconds. The auto shutoff feature is great, as I sometimes forget to turn it off. The display backlight is handy in low light situations. I use my gauge several times a day, and have yet to change the battery despite months of use. The only downside to this product is its size and weight, it's a hefty sucker.

Very good accuracy, 9-Volt battery, back lit display, nice size 7/8 hex nut for easy installation. Bought two, 100 and 200 psi

Very good gauge. Accuracy is excellent. Price is right.

I use this gauge to mix Nitrox. Works flawless.

Awesome gauge!

I used many pressure gauge, but also SSI is the best one you know.