The Osprey Nib-Block Kit includes the nib-block, a small plastic dowel, a rubber grip tool, Silicone grease tube (used to prevent small leaks)  along with G Nib Maintenance Guide that provides tips on inks to be used, step by step instructions on disassembly and assembly of the G Nib, along with Ink filling instructions.

The nib block itself is nothing but an improvised use of a regular thread spool. If you have one at home, you can use that too. But note that this kit gives you other tools to maintain your  pens in general.

These convenient accessories allow safe and quick swapping of friction fit/ heat-set nibs. Any nib unit that has an end tail should not be disassembled using  this nib block to avoid fracturing the end tail, instead use the soft rubber grip provided in this kit to pull out the friction fit nib and feed from those units.