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I have attached the image - this is inside underneath battery a small black plate above the touchpad - While removing battery this item came off . What is this item called so I can check for a replacement

The part is a trackpad shield to protect the trackpad. Clean off the glue and flatten it down, then just re-use. I use tesa tape along the edge of the trackpad case edge making sure not to get into the trackpad area. MacBook Pro 15" Retina Display Late 2013 Battery Replacement Here’s an image of its placement