I'm assuming there's a magnet. I hope these aren't just using weight to hold their position....
In my case for example, it is excellent for test points but somewhat challenging with soldered SMD component pads and very challenging if the density is high.
I assumed they were those bendable wire things like old style podium mic stands. Those tend to sort of stay where you put them, but not very precisely.
Thinking about it I might try a piece of low-profile bike chain and a copper wire and see if I can do better.
I mean the 'bendable' part. The nearest consistency I can think of would be a bag of sand. They are weighty but not rigid. They are not designed to hold their shape. Unfortunately this means that it takes very little sideways force to make them "flop" over.
Still, I can't recommend them highly enough. I use them all the time. Seriously, a PCBite plate with probes on-hand is now a permanent fixture on my main desk. If you do half as much fiddly electronics stuff as I do, they will pay for themselves. But you will also occasionally find them infuriating.