Will this injector work?

[Fitz7099]

I bought a pair of used injectors for a car that I am repairing/fixing/whatever.

There is the injector head, where the fuel comes out. There is a seal (?) that sits on the head. If you remove it a black plastic "cap" sits over most of the injectors nozzle. One of these caps is cracked and has a piece missing. Is this usable or do I need to replace it?

 

[flinguist]

Replace it. Mitsubishi part number MD087060. You should probably replace them all. They're less than 2 bucks a piece.