The Texas Instruments SN74F257D is a quadruple 2-line to 1-line data selector/multiplexer with 3-state outputs. It operates within a 4.5V to 5.5V supply voltage range.
The ON Semiconductor 74F257ASCX is a multiplexer with a 4 x 2:1 circuit configuration. It operates within a voltage range of 4.5V to 5.5V and has an operating temperature of 0°C to 70°C.