R16-503A/AD/B/BD Circular Button Instantaneous Lock Switch With LED 16mm 2/4Pin

Opening: 16mm. Pin: 2/4Pin. Pin: Tin plated copper. Latching(Self-locking): After pressing, the button is locked, and pressing again, the button can spring back. Specification: 2-pin without light, 4-pin with light.

eBay