Zener Diodes permits electric current to flow in the forward direction and also allow electric current in the reverse direction. It allow current to flow in reverse direction when the voltage is above certain value. Zener Diodes is suitable for various applications like voltage stabilizers or regulators, switching operations, surge suppressors for device protection, peak clippers, reference elements and in meter protection applications. It is specifically designed to operate in zero breakdown region. It is convenient to use and require low maintenance.