Front breakpads

[Uncredible]

Hi, I am currently repairing my front breaks, and the front pads that were in have this weird thing that I haven't seen before, the service manual says they are "With mass damper and anti-squeal spring" and this is not present on my new break pads, is this even necessary and what is its purpose?

I attached pictures of how it looks, you can clearly see that this is missing on the new breakpad.


I have just finished replacing the pads and disk on both my rear tires and that wen't pretty smoothly.