Genius!
These are perfect!  I started cutting my own hair at the start of the pandemic.  I had no experience other than watching haircutting videos.  I did a decent job but found it hard to get it even all around.  I've bought every tool I can find but none worked... until I tried the hairFins.  I hold the hair between my fingers as usual but now I have the hairFin to ensure I'm cutting the desired length consistently.  These work perfectly for me.  I use the 2 and 3 inch most.  Genius idea and great solution!
Rating: 5 stars