Authentic Refills: Designed specifically for Parker ballpoint pens Smooth Writing: QUINKflow ink ensures consistently smooth writing Vivid Blue: Beautifully pigmented medium tip ink captures your thoughts in vivid blue Reliable Performance: Each pen ink refill is engineered for reliable writing performance ISO Certified: Complies with ISO 12757.2 and Documentary Use standards for long-lasting documents 6-Count Value Pack: Offers value for money with 6 medium point refills Change Ink Color: Easily swap out the refill to change your ink color.