Parker Quink technology provides silky smooth writing with a specially formulated liquid that resists blockages. Each refill features a medium nib for general handwriting. For use with your Parker ballpoint pen, simply unscrew the pen's cap, remove the empty cartridge and insert a fresh refill for continued performance. 
 
Quink refill for Parker ballpoint pens
Parker Quink technology for smooth writing
Medium nib 1.0 for general use
Fine nib 0.8 for precision use
Simply unscrew pen body and replace old cartridge