This part is a kind of semiconductor called BF904.

Function of this product has N-channel dual gate MOS-FETs.

Manufacturers : NXP

Image and pinout :

Some of the text within the PDF file :

DISCRETE SEMICONDUCTORS DATA SHEET BF904; BF904R N-channel dual gate MOS-FETs Product specification Supersedes data of 1997 Sep 05 1999 May 17 Philips Semiconductors Product specification N-channel dual gate MOS-FETs FEATURES • Specially designed for use at 5 V supply voltage • Short channel transistor with high transfer admittance to input capacitance ratio • Low noise gain controlled amplifier up to 1 GHz • Superior cross-modulation performance during AGC. APPLICATIONS • VHF and UHF applications with 3 to 7 V supply voltage such as television tuners and professional communications equipment. DESCRIPTION Enhancement type field-effect transistor in a plastic microminiature SOT143B and SOT143R package. The transistor consists of an amplifier MOS-FET with source BF904; BF90 [ ... ]

BF904 PDF Datasheet Download