A transluscent material specially chosen to make this an eyedropper if required. It has an O ring fitted to the section to prevent leakage, although I always suggest that some grease be applied....belt and braces! Of course, it doesn't have to be used as an eyedropper, it is also cartridge/converter.
These pens are very light, weighing in at around 16g without the cap. It will be fitted with a JoWo nib of your choice, just advise me once purchased. Your choices are EF, F, M, B, 1..1mm stub, 1.5mm stub available in polished stainless or two tone (stainless steel). Gold available as an extra in F, M, B. It comes with a quality ink converter and will also accept standard international ink cartridges (not supplied. The pen will come in my branded box.
Please state your nib requirement in the comment section of your PayPal payment.