In the world of Attack on Titan, the members of the military are tasked with fending off the giant, man-eating Titans that live beyond the walls of their home. As viewers quickly find out, this is no easy feat — particularly given the fact that the Titans' only weak spot is at the nape of their necks, far higher up than most humans could ever hope to reach on their own.

And this is exactly why the 3D maneuver gear utilized by the various divisions of the military is so important. Without it, it's probably safe to say that the characters in the anime wouldn't stand a chance of defeating the Titans. After all, they barely manage even with the specially designed equipment.

But what else is there to learn about the 3D maneuver gear used in Attack on Titan? Well, these are 10 facts you might not know about it just from watching the series.

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10 10. The Gear Is Attached To The User As A Harness

The vertical maneuver gear works so well because it’s attached to the person using it with a harness. This means the person with the gear will need to completely entrust their movements to the equipment — but that’s the price one must pay to swing around hundreds of feet in the air.

The fact that the gear is built around a harness, though, does enable the characters of Attack on Titan to perform some pretty impressive moves while using it. Levi Ackerman can often be seen using the equipment’s setup to his advantage, spinning during his attacks to make the impact that much more successful.

9 9. 3D Maneuver Gear Is Made Up Of Several Pieces Of Equipment

While it's easy to view the 3D maneuver gear as being a singular piece of equipment, it's actually made up of many different pieces, each of which combines with the others to enable the user to fight. Some of the tools included in the structure of the gear are hand grips, grapple hooks, gas-powered mechanisms, and iron wire propellers with plug-in blades.

The handgrips and grapple hooks obviously allow the person using the 3D maneuver gear to direct their movements, while the gas gives them the momentum needed to "fly." The blades are for the most important part of using the gear: cutting open the Titan's napes.

8 8. Users Need Strength To Wield The Gear

During the anime's first season, viewers are treated to a training sequence, during which we see Eren and his comrades attempting to remain upright while using the 3D maneuver gear. This seems like an odd thing to train future soldiers for, but the reason becomes clear when one looks further into the equipment: Anyone who doesn't have a strong enough build will buckle, rendering themselves incapable of using the 3D maneuver gear.

And this is why Eren constantly flips upside down when attempting to use the equipment. Of course, we eventually discover that his particular gear was broken — but his struggles still demonstrate what would happen if someone without strong leg muscles were to use it.

7 7. The Steel Blades Used With It Can Only Be Made In Blast Furnaces

As fans might imagine, Titan flesh is pretty thick — meaning that anyone attempting to cut open a Titan's nape is going to need a pretty sharp blade to do so. And the blades attached to the vertical maneuver gear do the trick, but that’s because they’re made in blast furnaces. In fact, these blades can only be made in blast furnaces located in factory cities — otherwise, they just won’t work properly.

And even with the fact that they’re designed specifically for cutting into Titan flesh, the blades still wear down fairly quickly. Soldiers using them often carry extras with them, this way they can replace the blades when they get too dull.

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6 6. The Gas Mechanism Can Prevent Someone From Falling

While the grapple hooks are useful when it comes to shifting direction — and possibly when it comes to falling — it turns out that the gas mechanism alone can actually catch users of the 3D maneuver gear who fall off of high surfaces. Unfortunately, that's something that's all too possible in a series like Attack on Titan. Lucky for the series’ characters that their gas tanks are so powerful.

Of course, the more power and gas the characters use, the faster they’ll run out — so it’s still not advisable to be too clumsy with the maneuver gear. We’ve seen Mikasa and the others run out of gas before, and it’s not a pretty situation to be in.

5 5. 3D Maneuver Gear Is Difficult To Use In Open Spaces

Although the 3D maneuver gear comes in handy when fighting against Titans, it's actually difficult to make use of when in a more open landscape. That's because the grappling hooks are what allow the user to choose their course — but when there's nothing to latch onto, they're essentially floating blindly.

This is why Levi worries during the third season that he won't be able to get to the Beast Titan while fighting outside the walls. Of course, Erwin points out that he can use the crowd of Titans blocking their path as leverage. Fighting in open spaces may be more difficult with the 3D maneuver gear, but it’s doable if you’re creative about it.

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4 4. The Beast Titan Was Particularly Interested In The Gear

Attack on Titan's Beast Titan

When viewers are first introduced to the Beast Titan, he shows a special interest in the 3D maneuver gear utilized by the Eldians in Paradis Island. During his discussion with Miche Zacharias, he asks a lot of questions about how the equipment works, as he’s seemingly never come into contact with it.

After learning more about who the Beast Titan is and where he comes from, fans can deduce that he was probably interested in making a Marleyan equivalent of the gear at the time — or, at the very least, finding a way to negate its effectiveness against the Titans.

3 3. Anyone Who Can’t Use The Fear Can’t Join The Military

We mentioned that Paradis Island soldiers are trained to stay upright with the 3D maneuver equipment, but it’s also worth nothing that anyone who fails to do so will be dismissed from the military — no matter which regiment they’re aiming to join. Even if the gear only seems useful for the Scouts, it’s deemed crucial that members of the Garrison and Military Police know how to use it too — after all, the Titans have managed to breach the walls before.

And given that Titan attacks can be unpredictable, it’s probably a good thing that most of the military can use the equipment — even if they still have to, you know, overcome the fear of fighting Titans when they aren’t necessarily accustomed to it.

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2 2. There’s A Design Made For Fighting Other Humans

The 3D maneuver gear was obviously designed with the intention of using it against Titans, but the Military Police actually invented a version of the equipment that’s designed for fighting other humans. Dubbed “anti-personnel vertical maneuvering gear,” this variation is very similar to the original design, but it replaces the blades used against Titans with firearms.

This rendition of the gear was made to combat the Survey Corps, which the Military Police believed was getting too powerful and out of hand for its own good. Viewers see this in action during season three, when Levi and his squad fight Kenny’s gang within the walls.

1 1. There's Also A Design Made For Fighting The Armored Titan

Just as the Military Police got creative with their own variation of the 3D maneuver gear, the Scouts Regiment managed to tweak the equipment to work more effectively against the Armored Titan, whose outer layer of armor is impenetrable by even the best-made blades.

That’s why, during the most recent season of the anime, the Survey Corps created “Thunder Spears,” a version of the 3D maneuver gear that enables them to shoot explosive rods out of the section that would normally house the blades.

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