This part is a kind of semiconductor called 74HC4538.

Function of this product has Dual retriggerable precision monostable multivibrator.

Manufacturers : ON Semiconductor

Image and pinout :

Some of the text within the PDF file :

MC74HC4538A Dual Precision Monostable Multivibrator (Retriggerable, Resettable) The MC74HC4538A is identical in pinout to the MC14538B. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LSTTL outputs. This dual monostable multivibrator may be triggered by either the positive or the negative edge of an input pulse, and produces a precision output pulse over a wide range of pulse widths. Because the device has conditioned trigger inputs, there are no trigger–input rise and fall time restrictions. The output pulse width is determined by the external timing components, Rx and Cx. The device has a reset function which forces the Q output low and the Q output high, regardless of the state of the output pulse circuitry. http://onsemi.co [ ... ]

74HC4538 PDF Datasheet Download