"Strange piece" on toyota corolla 1999

Hi everybody I have this case with a friend of mine.He got some problem with his car and decide to check for himself the problem and find the timing chain was faulty so he buy the complete kit to repair the car.The proble is that he disassemble the car and leave disassemble for a couples of weeks in the garage., when he began to replace the pieces one piece appear and he can't figure out what is this piece .I try to help him and i'm in the same situation don't know what is .
I think that is a mix or another piece that dropped with the Toyota parts.
Any help will be appreciate
thanks

That part goes with the motor mount,dead weight to reduce vibration onto the inner fender body. Can live without it may not notice any difference.