Add units to variables on dash

I’d like to be able to use variables in my dash and be able to use units with it.

For example I have a variable that’s the humidifier level , and I have this so I can quick adjust the humidifier level.

Currently my dash has a number and quick up down arrows. But the number has no units so a user sees “40” but doesn’t know it’s 40%.

I simply want to be able to have it read 40% instead of 40.