I bought a similar gauge from a Strauss Auto in Brooklyn, but mine was either $16 or $26. Either that, or neither Strauss had the one I wanted & I got it online, I forget. Either way, it's an AccuGage brand dial gauge with a bleed valve & a pass-through. You hook it up to the tire, it gives you a reading. You hook your air pump up to the pass-through & start inflating. The needle jumps around while air is flowing, but you have a steady reading as soon as you stop pumping.
Ah, found a link to the MCN review:
Click here for PDF file. Accu-Gage EX-02.
I also picked up a compressor after reading an MCN review. It's a Slime 40001 Power Sport tire inflator, & it was $30 from
Amazon. It's not for air tools, but it's small, very portable, & powered off the bike's battery. Works a treat for filling your tire without resorting to a bicycle pump or pushing it to the gas station. Add a plug kit & it makes a flat on the way into work a 15-minute PITA instead of a 2-hour ordeal.
(A little history... 400 miles after my new rear tire in late December, I picked up a drywall screw & flatted out. I pushed my bike all over Astoria, Queens looking for somewhere that would plug a bike tire. It took about an hour & a half of sort of riding, sort of walking on the flat to find one, then half an hour for the guy to actually plug it. My boss was not happy. Yesterday, with the Slime pump, I was able to pump it up, park near work, then plug it at lunch time. No unhappy boss, no riding/walking on a flat.)
HTH,
-Kit