It's unusual to me only for the fact that hex bit sockets traditionally have a replaceable bit that is fastened into a socket with one of a few different methods like set screws, roll pins, or simply press fit. Some, like Bondhus, have detent ball equipped bits and are thusly held into a corresponding sized socket you presumably already own.
Now that I think about it, I've never seen a socket exactly like that. Even my old Proto 1/4 torx bit sockets have replaceable bits. That is unusual because it is machined from one piece, and is super stubby.
I may have missed it but what brand? I think it's kinda neat if it held up. Ball end hex tools obviously will strip before conventional hex ends, but that is the price you pay for increased access and angle.
Edit: I have found that while ball ends are handy, I only really use them for certain things. My go to Eklind .05-3/8" sae set and 1.5-10mm metric set are normal end. I do have separate individual ball end hex keys in a few sizes...smallest being 3/8" And 10mm, smaller than that and too easily snapped. I don't use really any metric sizes larger than that for now, but I have Bondhus ball ends in 7/16, 9/16, and 5/8 that are great. I'd like to get one in 1/2 as that is my most used size, and possibly a 3/4 if they make it. I think the larger sizes is where ball end truly shine.