Older monitors have that Horizontal width coil. The width gets smaller as you turn that magnet in. The big adjustment is usually made with a capacitor change.
Keep in mind that you can adjust the width with the monitor running, you just have to use a special plastic tool. It's a hex head plastic TV adjusting tool you can get at Radio Shack or some other electronics supplier. You can use a metal piece IF you cycle the monitor on and off. If you leave that metal wrench in there the electromagnetic field will get it hot in a second or two and it will burn the hell out of your hand.
If a monitor is off, you can pretty much touch any part of the electronics. It won't bite. The only thing that will byte is the suction cup, and on new monitors that won't either.
When you adjust that coil, keep in mind it's probably pretty old. I suggest you always use the plastic tool because that little magnetic disc sometimes gets stuck in it. A metal tool will shatter it. Test moving it up and down to make sure it's free. If it isn't, consider changing the cap, and you'd have to know what monitor chassis you have to do that. It's not really that big a deal. If it's just that cap you can just clip it off and solder a new one on the legs.
The rare one is in the K7000 (C39). All the others are not so rare. But find out what the monitor is and I can look up which one you need.