The included syringe is for applying/filling conductive gel between the 4.5mm main probe and the 2.0mm or 3.0mm depth regulator. It is **not for injection into the skin**. Please **do not remove the clear film/sticker from the regulators**. The transparent area is part of the regulator and is used to check that the gel is fully filled with no air bubbles before treatment. Make sure there is enough gel between the probe and regulator before use.