TISP4310T3BJR-S is a bidirectional thyristor overvoltage protector designed to limit overvoltages on telephone lines caused by power system disturbances or lightning strikes. The device features an industry-leading VDRM to V(BO) ratio with a repetitive peak off-state voltage of ±269 V and breakover voltage of ±310 V, utilizing ion-implanted breakdown region technology for precise and stable voltage triggering. It provides 2-point protection between Ring and Tip wires and is rated for multiple international surge wave shapes including TIA-968-A Type A & B surges, UL 60950 power cross protection, and ITU-T K.20/21/45 standards, with peak impulse current ratings ranging from 80 A to 150 A depending on wave shape. The device exhibits low voltage overshoot under surge conditions and is housed in an SMB package, making it ideal for modem and telecommunications equipment protection where reliable overvoltage suppression is critical.