@julsjewels Another great question that I want to know as well. I just watched a video someone linked to of an Australian physician demonstrating techniques for Botox on the forehead and he used one of these gizmos to avoid hitting veins and therefore preventing bruising. He marked vein locations directly on the skin in one color, then marked sites to inject in another and then was able to wiz thru the actual injections and not once did anyone bruise. The link is in Birdie's post titled "Victoriam Cosmetic Institute Spock". Am now binge watching his videos!