I tried one of those and was sorely disappointed, at least the model I had the arms were way too flimsy.
It's super easy to build one that is better, Lowe's sells wire by the foot. Get either 12 or 10 AWG wire, crimp alligator clips on it, and attach the other end to a piece of plywood with 2 screws, looping the wire first around one then the other for stability. This works way better, and if you find the arms are either too flimsy or not sturdy enough it's super easy to modify. I attached mine with machine screws and have 14awg and 10awg arms that I swap between depending on how heavy the thing I'm holding is. Eventually the copper wire will work harden and break, but I haven't had an arm snap in the 6 years I've been using this. Probably would cost 15 bucks total and the only tool you need to build it is a drill (assuming you have electronics tools already).
They can be useful but often the cheap ones are not that good / fall apart. You can also just build your own with heavier wire like used in home wiring and some quality crocodile clips. Attach to a heavy base.
I also recommend the blue tack on top of the crocodile clip positioners.
https://www.aliexpress.us/item/2251832787531236.html
Anyone having good/bad experience with this kind of tool?