A small pot of 10g
Silicon Grease can be used in various ways:
To ease a tight section back into the barrel
On Vaumatic sacs, when fitting into the barrel
On the Vacumatic unit when screwing back into the barrel
On tight section threads
On 'O' rings
On Sheaffer plunger rods, to ensure a smooth filling stroke
Will also provide a barrier against ink leaking when a screw in nib section is fitted into a barrel.
Colour of plastic pot may vary.