I had one of those cheap and nasty tyre inflators, the type to plug into an air line - cast alloy body, fitted with a short bit of black hose to connect to the clip on tyre valve fitting, brass air release valve plus large trigger to put air in and a round faced analogue pressure gauge built on the side of it with a black rubber surround for protection. Works well enough, but the gauge was hopelessly inaccurate due in part to its high maximum reading and cramped scale.
I also had one of those Draper digital pressure gauges - A round faced gauge, red 'on' button, with a blue rubber around it for protection, then a short hose to to a brass fitting for the valve. Very accurate, nicely engineered, but the brass end is poorly designed, this again with a deflate button. It was difficult to grip and difficult to locate on the valve - made worse by the end being designed to rotate.
So checking and adjusting my pressures was a matter of blow them up, then struggle with the digital gauge to get a reading.
Looking at the two items in the garage today, it looked as if it might just be possible to swap over the two gauges to combine inflator with my accurate digital gauge. The fitting for both gauges turned out to be identical, an external thread which was a perfect match.
Absolute bliss....
One single operation to inflate and adjust accurately. I had bought three pencil type digital gauges, simply because of the poor design of the Draper unit which I had thrown in a drawer.
I was on the point of lashing out lots of money on one of those expensive professional inflator units to solve my frustration - but this will do very nicely now :-)