SOT 89
The SOT-89 is a type of semiconductor package often used for low power, surface mount devices such as transistors and small-scale integrated circuits. The abbreviation "SOT" stands for "Small Outline Transistor," and "89" refers to the specific package style.
Compared to the SOT-23 and SOT-223 packages, the SOT-89 package is somewhat larger, allowing for better heat dissipation. It typically measures about 4.5 mm long by 2.5 mm wide, though exact dimensions can vary somewhat between manufacturers.
The SOT-89 package typically has three leads and is designed for surface mount technology, which allows for direct mounting and soldering onto printed circuit boards (PCBs).
As with any specific device, for detailed information such as pin assignment, electrical characteristics, or exact physical dimensions, you should refer to the manufacturer's data-sheet for the specific device in question.