My wrist where i can feel my pulse, the vein on my elbow, my thyroid gland, below my eye, forearm, and where the injection site would be if I was a tool. Same places on all of us with various effectiveness based on fat levels. Two neighbors also unmodified have it stick. I think a lot of people are to fat for them to notice, because out of 13 people only two that I have personally observed attempting it didnt have it work and they were both fat. Also one of them WAS vaccinated.