A 6mm 4-pin tactile switch is a standard, momentary micro push-button commonly used in PCB prototyping, breadboards, DIY electronics, and repair jobs for devices like microcontrollers or household appliances. These switches normally feature a Single Pole Single Throw (SPST) normally-open contact configuration, meaning the circuit is temporarily closed only when pressed.
Depending on whether you need a through-hole (DIP) or surface-mount (SMD) design, here are the top component options available: