The 2N2907 is a commonly available PNP bipolar junction transistor used for general purpose low-power amplifying or switching applications.
This transistor was made by several manufacturers; Texas Instruments released a data sheet for their version of this part dated March 1973.
Its transition frequency fT (where the current gain drops to one) under specified test conditions is 200 Megahertz.
[4] Other types of transistors with different properties and connections have different part numbers.
The prefix of each part number varies for each physical package type.