I use a Dynaplug Micro Inflator for maintaining tires away from home and would definitely recommend it. Compact and they hold up well. I keep one in my touring kit, and I ended up buying another one specifically to keep with the CT125 since it has tube type tires. I run it off an SAE pigtail from the battery, but it can also be powered off a cigarette lighter outlet or alligator clips to the battery terminals. It is a good practice to run the bike in neutral while using it so you're not draining the bike's battery.
www.dynaplug.com
It's also a good tool to have on hand for helping other riders. Not a great photo to show the tire inflator itself, but here's my 2022 Moto Guzzi V7 Stone Centenario 850 providing the 12v power (SAE plug is behind the passenger footpeg) to run the inflator to air up the tires on a friend's 1947 Harley Davidson EL. It's just the sort of thing that is convenient for morning pre-ride checks, rather than riding over to a gas station and hoping they have a functional air machine.
At home I use a DEWALT 20v Cordless Tire Inflator, it's easier for me to carry that over to a vehicle than it is to use most regular air compressors.