When your hands get tired from too much driving. All you need to do is stop and properly replace the steering wheel (as the instructions show) with a different kind. Then go on your way feeling much better. You can make longer trips with fewer stops and in more comfort
There is simply a release that alows the steerin wheel to come off when you want to take it off. Yes they are safe. Not sure why you would want one unless you have some kind of race car you plan on putting it in. Hope you figure out what you want to do.