I had one like a Bullseye (same shape, different color) for using on the race car at the track. It was a miserable piece of crap.

I bought a DeWalt inflator. It's a bit bigger but still portable, and it's automatic. Set your pressure and walk away. I checked it against my good tire gauge and it is spot on.

My old gun style I couldn't even give away. It went in the garbage.