There aren't many high quality mini-pens out there attachable to key chains, business backpacks, etc. I travel a lot and need a readily available pen when on my feet, in a car or plane for filling out passport forms, taking notes, etc. The Caro pen is perfect for that. It's more expensive than a throw away. But Craighill's customer service is worth the price. The bottom cap holding the ink cartridge (refills are widely available) came off (not unexpected given how much travel abuse I gave it). Hannah from Craighill not only took the effort to see if they could send me a replacement cap, but when Craighill did not have one on hand, they automatically sent me a replacement pen! Highly recommended pen. Highly recommended company to deal with!