An easy-to-assemble kit. (It probably helped that I'm an electrical engineer for a living and did it with a $1,200 Metcal soldering iron and a $4,000 stereotactic microscope, and just prior to doing this, I was soldering a TQFP-44 package on a microcontroller board. But still, I'd rate this as a kit a novice could put together without too much difficulty. I used lots of liquid flux and washed with isopropanol afterward, and the solder joints were quite nice, indicating that the land patterns on the board were good. PCB quality was also high.)
The design was good, and you can never go wrong with a 555 timer circuit. That it can run from a 9V battery without regulation was a nice bonus.
If I had to design one myself, since a red LED typically turns on at 1.7VDC, I might come up with something that'd run on a small microcontroller with internal regulation and could be powered by a coin cell. That'd make turning it into a pendant more practical. But still, for a straightforward design for an amateur to put together, this one was pretty good.
And shipping was quick, so I plenty of time to put it together for Valentine's Day and give it to my sweetie to underscore the fact that she's dating a dork.
Response from Magic Smoke | March 2, 2020
I'm glad it got to you in time, Eric. As a fellow dork, I am jealous of your soldering setup. A coin cell pendant is a wonderful suggestion!