The 7 year pen--The makers of this pen claim that the ink supply will last for 7 years of light/moderate everyday use. I just started using mine today, so if I can keep it for more than 3 weeks, I'll see how long it will last.
7 year pen - The Seven Year Pen is able to write meters a day for 7 years. This Swiss-made jumbo ink supply pen features large ink cartridge, super smooth black ink and long-life tip. Green body and nautical graphics.