Do you sell this black piece?

Hello,

Thanks for writing in! The piece you have pictured here is the track slider used on casement window hinges. I'm sorry to say that this is not a part sold separately from the hinge. If it is broken, you will need to replace the entire hinge assembly.

I'm sure we can supply you with a replacement for your hinge, I'll just need to see a photo of the other components and I'll need to know the length of the track that mounts to the window sill.

Please feel free to reach out with any questions you might have in the meantime.