JOAUIAX Non-Contact Voltage Tester,Electrical Voltage Detector Pen

Horrible pens. They will start to skip and not write shortly after you buy use them. It's as if the manufacturer has a bad design at the ball point tip not letting enough ink come out or ink is too thick for the design. Rarely will you get to use the whole cartridge. Tired of these pens not wanting to write. It is not just one batch it's all pens made.