This part is a kind of semiconductor called DB3.

Function of this product has 150mW Bi-directional Trigger Diode.

Manufacturers : Taiwan Semiconductor

Image and pinout :

Some of the text within the PDF file :

Small Signal Diode DB3-DB3TG 150mW Bi-directional Trigger Diode DO-35 Axial Lead HERMETICALLY SEALED GLASS Features —Designed for through-Hole Device Type Mounting. —Hermetically Sealed Glass. —All external suface are corrosion resistant and terminals are readily solderable. —High reliability glass passivation insuring parameter stability and protection against junction contamination. —Pb free version and RoHS compliant Mechanical Data —Case :DO-35 Solder Hot Dip Tin (Sn) lead finish —Terminal: Pure tin plated, lead free., solderable per MIL-STD-202, Method 208 guaranteed —High temperature soldering guaranteed: 260°C/10s —Marking : DB3/DB3TG —Weight : 0.1255 gram (approximately) D A B C Dimensions A B C D Unit (mm) Unit (inch) Min 0.45 3.05 25.4 1.53 Max 0.55 5.08 38.1 2 [ ... ]

DB3 PDF Datasheet Download