I have the same one shown in the video, and it was sold as a pet trimmer, for around dog's faces. I have used it for years, but not the way the video demonstrates. It works better if you anchor the other end of the seam, either with a clamp or at the edge of a drawer, or just between your knees. I always start the rip out by taking out a few stitches with the regular seam ripper. The same tool is sold as a men's mustache trimmer, but they get a few dollars more for it when it's named that. It certainly looks the same. You have to apply a drop of oil on the blades occasionally, and sometimes it has to be cleaned because lint accumulates when you do as much ripping as I do.

How about a self filling bobbin (while it is in the machine)?
We could think up a lot of neat inventions, couldn't we?

I bought one of these at Walmart, it is called a mustache & beard trimmer. It was only 7.99.

I did get one of these at a quilt show , I love it .

I got one at a quilt show and thought it was wonderful until it ate some fabric. Then I was more careful in how and what I was un-sewing. Then it died within a year. So I didn't bother to replace it - just bought a few of the standard seam rippers.

The one I bought is rechargeable.

Interesting.. I use a rotary cutter to rip my seams - the 18mm one that I got years ago. You have to be careful, but any thing you use to rip the seam can rip the fabric. I recently saw Eleanor Burns use her regular size rotary cutter to rip a seam on TV.