Replacement pencil insert for Mistral pencil kits.
These inserts may also be able to be used to convert ballpoint pen kits that take a Parker type refill to become a pencil. Careful shortening of the of the black push stalk with a sharp knife will usually be required in order to do so.
This pencil insert is refillable and comes with 0.5mm leads. It is also available with 0.7mm leads.