Any idea what kind of sweing piece this is? It's retractable.

I found this beautiful piece in a Box of vintage sewing stuff. I'm not sure what it is. It looks like it has a shell casing. It opens and retracts like a mechanical pencil and something sticks out of it, I'm not sure if it's a to or what it is and no it does not write. Thanks for your help in advance. I'm really curious as to see what this actually is. I'm wondering if it has to do with patterns some kind of Mini hole puncher for patterns?