The device is easy to use. I found it safe and mostly comfortable. The blade cartridge seems to have been 3d printed. Instead of ridges to give grip, make an indent with a wall to cradle your finger. The ridges give grip, but you have to press with a bit if force to get it to move…after doing 30 or so, my finger was a little sore. It also would be nice to have the blade cut lower. Some brands have a glue line lower than others, and for those the top comes off with the bag still glued to the plastic cup.
