Can not find Sash guides please help

A home owner from Nv says:
Replacing spiral springs on my vertical sliding single hung window and i dont have the brackets on the bottom of the sash. I also need the sash guides that screw into the sash.
User submitted a photo of a window balance.
Profile picture of Paul
Paul from SWISCO responded:
We can make this balance, though it will need to be a custom order. Before we continue, can you tell me the length of the outer tube of your balance? Can you also tell me h ow heavy your sash is?

I'm not sure about that black piece. I don't recognize it. Can you tell me what its function is? Could I also see a picture of one that isn't damaged?
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