The original "parent" is the
Omron B3F series tactile switch. The chinese have copied them and made it a generic with many different plungers built-in, instead of Omron's approach which requires additional buttons.
There are two (base) sizes, 6x6mm and 12x12mm. Plungers come in 0.5mm increments.
I think you have a 12x12mm, H=5.5mm plunger (or 6mm), through-hole part.
Search fleabay or ali for 12x12 tactile and you will find them.