Leica no longer sell their original plastic part to independent repair shops, requiring you to send your lens to Germany to replace the part at an exorbitant cost for a trivially easy job. Anyway, the original part is rubbish - doesn't provide a good grip and breaks easily. My designs provide a more secure grip, and won't break like the plastic version. They are also designed so that in the unlikely event that you fit the tab with enough force, it comes off before the lens itself is damaged. They affix without gluing the tab to the lens, and are perfectly removable if you want to swap it out for a different one or back to the original spec.
Enquiries for tabs for other lenses welcomed.