Back in the day when I used to repair computers I always kept several of these on hand. It was guaranteed that after a lightning storm I would get calls from customers saying their modem quit working.
You could get cheaper modems but the Modem Blaster always worked regardless of what system I put it in and I never had one that I installed fail.
DSL eventually killed the market so I ended up with a few left. I found them in storage the other day and thought that someone could use them.