This part is a kind of semiconductor called TPB.

Function of this product has TRISIL.

Manufacturers : STMicroelectronics

Image and pinout :

Some of the text within the PDF file :

® TPB SERIES TRISILTM FEATURES BIDIRECTIONAL CROWBAR PROTECTION. VOLTAGE RANGE: FROM 62 V TO 270 V. HOLDING CURRENT : IH = 150mA min. REPETITIVE PEAK PULSE CURRENT : IPP = 100 A, 10/1000 µs. UL RECOGNIZED FILE # E136224 DESCRIPTION The TPB series are TRISIL devices especially designed for protecting sensitive telecommunication equipment against lightning and transient voltages induced by AC power lines. They are available in the CB429 axial package. TRISIL devices provide bidirectional protection by crowbar action. Their characteristic response to transient overvoltages makes them particularly suited to protect voltage sensitive telecommunication equipment. CB429 SCHEMATIC DIAGRAM COMPLIES WITH THE FOLLOWING STANDARDS: CCITT K20 VDE0433 VDE0878 IEC-1000-4-5 FCC Part 68, lightning surg [ ... ]

TPB PDF Datasheet Download