An ESD wrist strap which is also called antistatic wrist strap or ground bracelet. It is an antistatic device used to safely ground a person working on very sensitive elctronic equipment, to prevent the buildup of static electricity on their body, which can result in electrostatic discharge (ESD). It is used when touching the device or handling boards or application-specific integrated circuits. It consists of a stretchy band of fabric with fine conductive fibers woven into it, attached to a wire with a clip on the end to connect it to a ground conductor. The fibers are usually made of carbon or carbon-filled rubber, and the strap is bound with a stainless steel clasp or plate.  It is connected to ground through a coiled retractable cable and 1 megohm resistor, which allows high-voltage charges to leak through but prevents a shock hazard when working with low-voltage parts. Where higher voltages are present, extra resistance (0.75 megohm per 250 V) is added in the path to ground to protect the wearer from excessive currents; this typically takes the form of a 4 megohm resistor in the coiled cable (or, more usually, a 2 megohm resistor at each end).