Magnufluxed, yellow tagged tail rotor drive gear for a Bell 47 helicopter. See attached IPC page for exact part number, this is item 2 in the IPC page.
The part itself is marked as a -1, but the yellow tag is marked -3. Part number 47-620-568-1 is the "Gear Assy", which this is not. This is the single gear, which is part number 47-620-568-3.