This Telco Surge Suppressor protects against electrical surges and spikes. It has a low shunt capacitance to reduce signal loss. It Protects two center wires. Manufacturer: Black Box Corporation. Manufacturer Part Number: SP365A-R2. Brand Name: Black Box. Product Name: Telco Surge Suppressor. Product Type: Surge Suppressor/Protector. [Technical Information] Dataline Protection: Fax/Modem. [Warranty] Limited Warranty: 5 Year.