74HC14 Hex Inverter Schmitt Trigger

 74HC14 — Hex inverter with Schmitt-trigger inputs

Six inverters in a 14-pin DIP, each with a Schmitt-trigger input.

The hysteresis cleans up slow, noisy or ringing edges into sharp digital transitions — which is what you want for reset circuits, mechanical switch inputs and long cable runs. Use this instead of a plain 74HC04 whenever the incoming edge is not crisp.