Let me start by saying I not only have never seen one of these before but this has to be the most complicated 0.5mm pencil ever made. I would think it is from the 70s and it was made by the Sheaffer Pen Company. I include the instructions because they are detailed. The pencil works well and it comes with three floating lead protectors. One is in the pencil. As with other pencils, lead is stored under the eraser but only for storage. You put one piece of lead in each of the three lead protectors. Once one is loaded in the pencil the extender rod pushes the lead out through the lead protector. When lead is low you will see a red signal which will appear in the lead supply indicator window. The thing does work well but to many clicks on the chrome plunger cap and the whole lead protector will start to come out. Add one to your collection if you can find one.