The SN74HC05N is a hex inverter with open-drain outputs. Supply range is 2V to 6V. Quiescent current is 2 µA max. Propagation delay is 20 ns at 6V with a 50 pF load.
Open-drain output current — the 5.2 mA sink limit
The output low current is 5.2 mA per channel. That's the maximum sink current when the output is pulled low. For an LED indicator, that's plenty with a series resistor. For driving a relay coil or an optocoupler LED, check the load current — if it exceeds 5.2 mA, you'll need a transistor buffer or a higher-drive part like the SN74HCU04PWT (same inverter function, same 5.2 mA sink, but push-pull outputs instead of open-drain). The open-drain version trades push-pull speed for wired-OR flexibility.
Active production, ROHS3, and sourcing
It's ROHS3 compliant, so it passes EU RoHS and most medical-device material restrictions without an exemption.