I saw this advertised online via eBay and sold/shipped from China. I ordered one two weeks ago and it arrived.
I find it is a great diagnostic tool/aide while I have the lid off my Apple II+ and am still finishing up on my power supply issues. It's neat to be able to watch hands-free and hands busy elsewhere, what all the voltage busses are doing when disk drives are doing there thing and diagnosing a weak power supply or what something I'm doing is effecting any of the voltage busses, if it is.
For me it's a great, simple, and safe diagnostic tool/gadget to watch my voltage busses as I'm tinkering around with other things in my Apple retro projects. It cost more for shipping from China than it cost for the device. $40.00 total delivered in two weeks. Heck some things in the USA are taking me two weeks to get from CA to PA. It's a neat work bench toy and I really like it. Well designed, parts lay out, and made.
My new universal power supply is working great. At the moment I have 5 floppy DISK II type drives stacked vertically to the right of my Apple II stand and the are cable connected to three interface cards, all hooked up and working great. And the voltage busses are rock solid. This is sort of a stress test on things at this time. Next week I should get the re-cap kit for my original power supply and then I'll put that back in and see which power supply works the bests ... the original re-capped one or the new "universal soldier" one. Once I get things all buttoned up I'll likely only have 3-4 Disk II drives connected, with the others as spares.
See the picture below of the Power Supply Voltage Monitor Card in action: