ETP01-xx21 Transient Surge Arrestor The STMicroelectronics ETP01-xx21 series low capacitance transient surge arrestor for 100 Mbit/s Ethernet lines is designed to protect high data-rate communication networks. The STMicroelectronics ETP01-xx21 uses planar technology to combine a high surge capability to comply with Telcordia GR-1089 Intrabuilding and ITU-T K20/21 standards and low capacitance to avoid distortion of high-speed signals such as Ethernet. This STMicroelectronics transient surge arrestor delivers differential and common mode protection and Trisil™ technology that is not subject to aging and provides a fail safe mode in short circuit for better protection. The ETP01-xx21 provides protection against telecommunications surge standards on 10/100 Mbps Ethernet, Ethernet Gigabit, and T1/E1 line cards.