The gel pads peeled off the plastic backing smoothly and stuck to my skin without any air bubbles, which I wasn't expecting. They held their stickiness through three full sessions before I swapped them out, and the pack lasted me over a month with regular use.
Honestly, I just appreciate having these on hand the second the old ones start peeling at the edges. The adhesive sticks to the skin just as well as the originals, so my sessions stay uninterrupted without any fiddly re-pressing.