The 74F251D is a high-speed 8-input digital multiplexer. It provides, in one package, the ability to select one bit of data from up to eight sources. It can be used as a universal function generator to generate any logic function of four variables. Both assertion and negation outputs are provided.
On-Chip Select Logic Decoding
Inverting and Noninverting 3-State Outputs
SOIC 16 package. Actual brand may vary from picture.