A small holder for two spools of thread (recommended within 20mm x 55mm or 0.75" x 2.125") and up to 18 sewing needles (recommended within 35-41mm or 1.375"-1.625"). The cap twists on and off, there should be no need to pull with force if the locking ridge is aligned properly. All parts are interchangeable.

The prints in the picture are “Needle and Thread Holder Cap” and “Needle and Thread Holder Chamber.”

Want to see another variation? Let me know with a comment.