The plastic cover unscrews, allowing the owner to manually add gradations from 15 to 30 psi. Not sure why it doesn’t have them, but it’s an easy fix I guess.
The stock gauge on the Tapright regulator is 0 to 60 psi. I don't see going over 12 psi on my kegs and this gauge provides more range to see small differences in pressure. The regulator is another story - how to adjust the pressure in small steps takes some practice.
I'm going to look for another gauge for pressurized transfers out of my new chronical fermenter because I need to operate between 1 and 2 psi to avoid blowing the chronical lid off. It's a little hard to see that small of a difference on this gauge.
Wish I could submit pictures. Purchased two gauges. One gauge read One PSI when received, with no input. Second one, the needle was hard against the zero-stop pin. Flipping the needle over the pin, it went to about MINUS Five or Six PSI. And this one has an abrasion in the center of the lens - cosmetic.
Easily fixed, pry the needles carefully off the little pin, and press them back on reading Zero.
So, cheap Chinese product, with poor Quality Control. Surprised? Not really. Should work OK after the fix above.