Doctor Who’s title character is as sharp as a tack, there’s no two ways about it. No matter how impossible a situation seems, the Doctor always has a plan to stop the baddies and save the day. With a brain like his (and now hers), and twice the heart, the Doctor is exactly the kind of person you wouldn’t want to cross.

The Doctor and his/her companions always manage to get themselves into scrapes, but on the bright side, they always manage to get themselves out again. But, they’d have a heck of a time thwarting their enemies without the Doctor’s beloved Sonic Screwdriver. Here are 10 things only real Doctor Who fans know about that fantastic little tool.

10. It Was Once Written Out Of Doctor Who

Who isn’t a fan of the Doctor’s Swiss Army knife-like pocket tool? It may not work on wood, but it can do a lot of other cool stuff, like unlock doors, cut through metals, light candles, act as a flashlight and, of course, tighten and loosen screws.

How could anyone not love this handy, dandy screwdriver? Well, apparently, one person. The Sonic Screwdriver was introduced in the ’60s but it was written out in the ’80s when producer John Nathan-Turner felt it limited the show because the Doctor relied on it so much. The Sonic Screwdriver made another appearance in the 1996 Doctor Who movie, and it’s stuck around ever since.

9. The First Doctor Never Used A Sonic Screwdriver

William Hartnell, the First Doctor, never even used a Sonic Screwdriver when he held the office of Everyone’s Favorite Time Lord. The Doctor’s most iconic piece of tech didn’t make an appearance until the Second Doctor, played by Patrick Troughton, came on the scene.

Peter Davison, the Fifth Doctor, lost his Sonic Screwdriver when it was destroyed by a Terileptil in the ’80s, and the device didn’t emerge again until Paul McGann starred as the Seventh Doctor in the 1996 movie. When the series was rebooted in 2005, Christopher Eccleston’s Doctor Nine had a Sonic Screwdriver that was more closely linked with the TARDIS; so much so that the TARDIS could produce copies of the device on command.

8. It Can Be Used As A Weapon… Well, Sorta

When it comes to weapons, the Doctor isn’t a big fan. But, when you get into as many scrapes as the Doctor, you’ve got to have some way to defend yourself, even if your weapon of choice doesn’t pack a permanent punch. Once again, the Sonic Screwdriver has the Doctor’s back!

The Doctor wouldn’t hurt a fly, so the Sonic Screwdriver is not designed to kill or even injure the Doctor’s opponents. However, it can temporarily stun the Doctor’s enemies by emitting a burst of painful sound. How the heck could an alien monster be expected to chase after a Time Lord when a shrill, high-pitched siren is going off? It’s nearly impossible.

7. There’s More Than One

The Doctor’s Sonic Screwdriver is so impressive that it’s inspired several copycats. Not only did the Doctor’s former companion, Sarah Jane Smith, make use of a sonic lipstick in her own spin-off series Sarah Jane Adventures, the Doctor’s nemesis, the Master, also managed to get his hands on a Sonic Screwdriver knock-off, too.

In season four (of the new Doctor Who, that is), we learn that two other characters also have their own Sonic Screwdrivers. The Adipose nanny, Miss Foster, and River Song. But, you know who doesn’t have their own Sonic Screwdriver? Us. And we’re not happy about it.

6. It’s A Combination Of High And Low Tech

Don’t get us wrong, we’re not dissing the Sonic Screwdriver. That little probe’s the stuff a science fiction fan’s dreams! But this impressive feat of Time Lord tech does have its foibles. Like modern day earth technology, the Sonic Screwdriver must be charged from time to time, and, as we mentioned before, it doesn’t work on wood.

Still, the Sonic Screwdriver is a delightful mix of high and low tech. It can be used for something as complex as hacking computers and enabling cell phones to work throughout all of time and space. It can also, however, be used for tasks as mundane as installing cabinets and uncorking champagne bottles.

5. Eleven’s Sonic Screwdriver Broke New Ground

When Matt Smith took over the TARDIS in “The Eleventh Hour,” his predecessor’s (David Tennant) Sonic Screwdriver was destroyed after it malfunctioned when Eleven tried to use it to signal an Atraxi ship. The TARDIS then presented him with a brand new Sonic Screwdriver, and this one had an awesome updated feature.

Previously, the Sonic Screwdriver had to be controlled manually, but Eleven’s screwdriver could be controlled telepathically. All the Doctor had to do was think about what he wanted it to do, point, click and bibbidi-bobbidi-boo, it was done. Of course, the updated model still didn’t work on wood, but at least it’s a step in the right direction.

4. Thirteen Doctor DIY-ed Her Sonic Screwdriver

When Twelve (Peter Capaldi) regenerated into Thirteen (Jodie Whittaker), the Doctor found herself separated from the TARDIS. And since the TARDIS had produced the previous regenerations’ Sonic Screwdrivers, she also found herself without the Doctor’s most crucial tool. But, the centuries-old Time Lord wasn’t about to let that keep her down. She built her own Sonic Screwdriver!

Comprised of Sensa crystals and scrap metal, Thirteen’s Sonic Screwdriver looks amazing and does all of the neat stuff the previous Sonic Screwdrivers could do. To keep track of her trusty new pocket tool, the newest regeneration of the Doctor sometimes stores her Sonic Screwdriver in a fanny pack, along with her psychic paper.

3. The Screwdriver Wasn’t Always A Screwdriver

Early on in Peter Capaldi’s run as the Twelfth Doctor, he revealed that he no longer had the Sonic Screwdriver; he had replaced the device with a pair of Sonic Sunglasses. The Ray-Ban shades had its own set of awesome features, though.

Twelve used his Sonic Sunglasses to eavesdrop on peoples’ conversations, communicate with Gallifreyan battleships, rebuild the TARDIS, and to read his email. The Sonic Sunglasses proved particularly handy when Twelve was temporarily blind, as it provided helpful information (height, weight, age, etc) about the people and aliens he encountered. Eventually, the TARDIS provided Twelve with his own Sonic Screwdriver, and while we were happy to see it back, we still miss those sweet sunglasses.

2. This Time Lord Tech May Become A Reality

When it comes to the world of electronics, there’s very little the Sonic Screwdriver can’t do. It can disarm robotics, fix computers, provide medical scans, detonate bombs, track alien villains, provide geolocation, and so much more. It’s an impressive device, but is it impossible to recreate? Scientists say, maybe not.

While producing a Sonic Screwdriver as sophisticated as the Doctor’s is probably light years ahead of us, scientists have figured out how to use acoustic waves, which act a lot like electromagnetic waves, to levitate small objects. The acoustic radiation force, if it’s strong enough, can push objects in a straight line and suspend things in mid-air. That may be one small step for man, but it’s one giant leap for Doctor Who fans.

1. The Sonic Screwdriver And The Doctor Have Something In Common

You might think there have been dozens of Sonic Screwdrivers, and, technically speaking, that’s not wrong, but it’s not totally right, either. See, in “The Day of the Doctor,” the War Doctor reveals that even though the Sonic Screwdriver has seen many incarnations, it’s still the same tool. That’s right, just as the Doctor is the same Time Lord, but with many faces, the Sonic Screwdriver is the same piece of tech, but with lots of exterior updates.

If you think about it, this little piece of trivia helps explain why each Doctor has their own unique Sonic Screwdriver, as opposed to their predecessor’s. Each new regeneration of the Doctor is completely unique, so it only makes sense that their favorite Time Lord tool is, too.