SN54HC257, SN54HC258, SN74HC257, SN74HC258 QUADRUP.
54HC257 - QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS
SN54HC257 - QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS
M54HC257 - Rad-hard high speed 2V to 6V CMOS logic
CD54HC257 - Quad 2-Input Multiplexer
SNJ54HC257J - QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS
54HC257 - Rad-hard high speed 2 to 6V CMOS logic