If your Waterman pen twists to deploy the point, it's a ballpoint. Your Waterman ballpoint pen is always there when creativity demands spontaneity. The refills ensure your Waterman ballpoint pen is always ready to produce bold, flawless lines. The pen ink refill is filled with intensely dark black/blue ink for enduring impact and clarity. Refilling is easy with these oil-based, waxy Waterman ballpoint pen ink refill. To replace, simply unscrew your Watermen pen, remove the empty cartridge and reassemble the body. The durable fine/medium point rich ink combines to create beautiful flawless lines on most surfaces.