Some light hints that may point you in the right direction:
Hint 1
The assembly is a part of a larger machine.
Hint 2
Several assemblies are meant to move side by side in unison.
Hint 3
The square-ish shaped piece is plastic that will wear down and be replaced.
Piano wire hammer/striker…can’t remember the technical term.
Hammer is the correct term, but that’s not what they are. They come from a machine.