Finger pricking devices are are automatic devices used by people with diabetes to pierce the skin so that a blood sample can be extracted for testing. They insert a lancet (a very short, fine needle) into the skin using a spring mechanism. The depth at which the needle is inserted can be adjusted depending on the thickness of the skin.
Lancets are available in different sizes, or gauges. The higher the gauge, the smaller the width of the needle. A higher gauge lancet is generally less painful, however, you may not get enough blood to test with the higher gauge needles.
Lancets are designed to be used only once. If they are used more than once they become blunt and painful to use.