Gruen Factory stem for caliber 510 - new in envelope

GRUEN factory stem for caliber 510 and perhaps others, new in sealed envelope. I likely have several of these so the one you get may differ slightly from the images. I specialize in hard to find watch parts and all watch parts are unconditionally guaranteed. If you need a part for a Swiss watch I likely have it so feel free to inquire. Images do a marginally adequate job of representing the item.