This series will be End of Life (EOL) on December 31, 2017 and is not recommended for new designs. Replacement will be the SMCJ series . The SMC series is designed to protect voltage sensitive components from high voltage, high energy transients. They have excellent clamping capability, high surge capability, low zener impedance and fast response time.The SMC series is supplied in Littelfuse's exclusive, cost-effective, highly reliable package and is ideally suited for use in communication systems, automotive, numerical controls, process controls, medical equipment, business machines, power supplies and many other industrial/consumer applications.