The 3B3S-300 premium series 5-pin solid-state protector module is designed to provide superior transient and power fault protection for most standard telephone line applications. These solidstate modules are particularly suited to applications that require the protection of very sensitive digital equipment due to their nano-second reaction time. The balanced configuration of these modules provides the best protection against a line-to-line, metallic surge, where there is a large voltage differential between the two sides of the circuit. The characteristics of the solid-state protector are far superior to gas tube technology in speed of response and are virtually immune to overshoot, aging, and failure due to repeated tripping within rated limits. Balanced operation. Integrated Test Points. UL & cUL listed, R.U.S. approved. Designed to meet or exceed Telcordia standards