TL;DR: Head straight to checkout to save 40% on this tiny keychain pen before they’re sold out.

We all carry keychains, but this one is different. It can write underwater. It opens boxes. It can even survive a fire. That’s why it’s becoming one of the most coveted gadgets in our shop, and why you should put one on your keyring.

Owning the ForeverPen™ means you’d always have a pen handy—and it wouldn’t take up needless space in your pocket, bag, or car console. It’s less than an inch long, so you won’t even notice it’s there until you need it. You can order one here for only $23.99 (reg. $40), but we don’t have many left in stock, so act fast.

Another cool feature? It uses solid ink, so don’t worry about smudges, leaks, or running out of ink at the worst possible moment. When you need to cut something open, its pointed titanium tip works as a multi-tool in a pinch.

Check out now to get your ForeverPen™ at $23.99 before we’re sold out (reg. $40).