David Oscarson’s latest creation honors Alexander Fleming, the man who discovered Penicillin.

The Alexander Fleming Limited Edition Collection feature both a roller-ball and a fountain pen. Both feature Fleming’s signature and are decorated with the chemical formula for penicillin. The engraving is coated in a hard enamel. The background of the pen looks like antibiotics under a microscope.

The pens come in four different color options. The fountain pen costs $5,600, while the roller-ball version costs $5,400. They will only be available for a limited time.