Why Do Stormtroopers Have These Small Plates With 0ll on Their Back?

Stormtroopers are often humorously known for their tendency to miss shots, but that’s not the focus of this article. 

As a Star Wars fan myself, I’ve always been intrigued by a particular feature of the Stormtrooper armor – the ‘OII’ plates on their backs. 

Their purpose wasn’t immediately clear, which only added to my curiosity. After some research, I’ve uncovered the exact function of these ‘0II’ plates on every Stormtrooper armor.

So without further ado… 

The Purpose of the ‘OII’ Plates

By now, you might be wondering about the ‘0II’ plates on the back of every Stormtrooper, right? Let’s dive straight into it. 

These plates house a power pack and a small air supply. This detail is confirmed in Star Wars: The Visual Dictionary, a reference book by David West Reynolds, first published by DK Publishing on October 5, 1998.

Within the book, you’ll come across detailed information about Stormtroopers, including a data file that reveals: “A power pack and pressurized gas system in the stormtrooper armor backplate allows a trooper to survive even in the vacuum of space for limited periods. For extended exposure to open space, troopers wear space backpacks with extended life-support capacity.”

So with that information, I have researched a little further.

The power pack or power cells were used to create blaster bolts, while the air supply supports the helmet’s air filter feature.

And according to starwars.fandom.com, Stormtrooper armor is equipped with air filters and is fully sealed to protect against chemical and biological attacks. It can even shield the wearer in a vacuum for a short period. 

A tank mounted on the back holds an emergency oxygen supply that lasts for 20 minutes, and the body glove offers some thermal protection.

If a mission extends beyond 20 minutes, the air supply comes into play. This additional air supply allows a Stormtrooper to survive for up to another 20 minutes. 

Other Components for Stormtrooper Armor

In addition to the power pack and air supply housed in the ‘0II’ plates, the Stormtrooper armor incorporates various other components, each with a specific function and location.

The Stormtrooper armor and equipment are crafted to the Empire’s exacting standards, ensuring exceptional durability.

Gloves: These can be energized during close combat to deliver stun shocks, an optional feature that can give Stormtroopers an edge.

Stomach Armor: This section houses a Manual Suit Seal and environmental controls, crucial for survival in diverse conditions.

Thigh Armor: This part features a reinforced alloy plate ridge, adding an extra layer of protection.

Lower Right Leg Segment: This segment contains the suit’s auxiliary power cells.

Left Upper Side of the Shin Armor: This includes a knee-protector plate, designed for comfort when adopting a kneeling firing position.

IFF Circuitry: Located at the back of the suit, this circuitry is used for identification and command purposes.

Resonator: This device, used to open secure doors, is another key feature of the armor.

Personal Energy Shield: Issued specifically to high-value Stormtrooper commanders, this shield provides an additional layer of protection during combat.

In addition to the armor itself, every Stormtrooper is equipped with a utility belt and a backpack for certain missions

The utility belt includes:

• A high-tension wire
• Two grappling hooks
• Four spare E-11 blaster rifle power packs
• Three ion flares
• Energy rations
• A spare C1 military comlink hardwired against jamming
• Three water packs
• Two medpacs
• Two blast energy sinks
• A thermal detonator
• Combat de-ionizer
• wrist binders for capturing prisoners
• Electronic lock scrambler/descrambler

As for the backpack, if you recall from the data file I mentioned earlier, it attaches to the backplate of the Stormtrooper. Inside this backpack, you’ll find:

• An extended air supply that allows a Stormtrooper to survive up to twenty minutes in a vacuum
• Additional communications gear
• Cooling systems
• Mortar launchers
• A heater (contained in the Snowtrooper backpack)
• Additional rations
• An encrypted telemetry transmitter, a small embedded disc that allows troopers to identify friend from foe amidst identically armored Stormtroopers
• Rechargeable cells that power the armor’s electronic components for up to 240 hours on a standard charge

Not Every Trooper Has the Same Gear on Their Back

So now that we’ve covered the standard ‘0II’ plate and what it does, let’s clear something up: not every trooper in Star Wars has the exact same backpack.

The classic ‘0II’ backplate is what we usually see on standard Imperial Stormtroopers—the all-white guys we see throughout the Original Trilogy. That’s their baseline: a sealed system with a small power pack, a limited air supply, and short-term survival in a vacuum. Basically, your all-purpose foot soldier setup.

But when it comes to specialized troopers, that changes. These guys often have mission-specific backpacks and gear depending on the environment or their role. Here’s a quick rundown:

Scout Troopers

Scout Troopers don’t wear the standard ‘OII’ plate you see on regular Stormtroopers. Instead, they carry a slimmed-down backpack designed for speed and agility, perfect for fast-moving recon missions. According to The Visual Dictionary of Star Wars (1998), their backpack holds extra gear tailored for their role.

This includes long-range communication equipment, terrain scanners, and sensor tech—all essential for navigating unfamiliar or hostile environments quickly. These troopers are built for stealth, mobility, and hit-and-run tactics—not for heavy firefights or long-term survival.

Snowtroopers

Snowtroopers are the Empire’s cold-weather specialists, and their gear proves it. These troopers don’t just throw on winter coats and call it a day—they’re outfitted with advanced environmental systems designed to keep them alive and combat-ready in freezing temperatures.

The most critical part of their loadout is the snowtrooper backpack. It’s more than just storage—it houses a powerful heater system, complete with a liquid pump and integrated suit heater controls. This ensures their armor stays warm and operational even in subzero climates like Hoth. There’s a surplus power indicator and outlet for external gear, along with a communications unit and a homing beacon for coordination in whiteout conditions.

Their chest plate works in tandem with the pack, reinforcing warmth and protection. It includes a power cell monitor, heater controls, and compartments for rations—so troopers can operate for long stretches without resupply. The reinforced back plate and adjustable straps make sure everything stays in place during intense combat or rapid movement.

Flametroopers

Flametroopers weren’t your average frontline troopers—they were fear weapons. Deployed by the Empire and other military factions across different eras, these units traded defense and mobility for raw destruction. Instead of the standard ‘OII’ power pack, Flametroopers wore a fuel-heavy backpack that powered their signature weapon: the flame projector.

As noted in Jedi: Fallen Order, their flame rifles rely on a combustible fuel source that overheats and requires a cooldown time between bursts. That means they’re designed to hit hard, force the enemy out of cover, and reset, turning entire corridors into fire traps

The backpack is entirely devoted to fuel storage, built to support the trooper’s flamethrower with a steady supply of pressurized combustible liquid. Unlike other trooper units, Flametroopers sacrifice long-term survival gear, advanced comms, and support tools for raw offensive capability. They’re not equipped for drawn-out combat—they’re designed to deliver maximum destruction in a short window, overwhelming enemies with fire before the weapon overheats and needs to cool down.

Sandtroopers

Sandtroopers are the Empire’s desert specialists, and everything about their armor is built for long deployments in extreme heat. We first see them in Episode IV: A New Hope, deployed on Tatooine with orders to recover the stolen Death Star plans. Their mission required them to operate in harsh desert conditions for extended periods, and their gear reflects that.

Sandtroopers still wear the standard ‘0II’ plate on their back. However, they also carry an additional SD-48 survival backpack, specifically designed to support long-range missions in the desert.

According to the Star Wars Databank, the backpack includes extra rations and water, allowing Sandtroopers to operate independently for days without support. The Visual Dictionary of Star Wars (1998) also expands on this, noting that the Sandtrooper’s backpack can carry micro-vaporator water-gathering canteens, augmented cooling modules, and a wide range of base camp and field operative gear. All of this makes them well-equipped to endure the harshest desert missions without relying on constant supply lines.

Jumptroopers

This trooper goes by many names—Jet Trooper, Rocket Trooper, or Jetpack Trooper—but they all refer to the same airborne enforcer: the Jumptrooper. Their gear is nearly identical to that of standard Stormtroopers, with two major differences—the addition of a jetpack and a missile launcher.

The focus here is pure mobility. The jetpack is equipped with gyro stabilizers for mid-air balance, directional thrusters for agile movement, and enough fuel for short bursts of flight or high-powered leaps. It’s not made for long-range travel, but for fast repositioning in chaotic urban combat or vertical battlegrounds, like those we see in Star Wars: Battlefront.

But that agility comes at a cost. The jetpack’s internal space is fully dedicated to propulsion, meaning there’s little to no room for extended oxygen reserves, rations, or advanced communications systems. These troopers aren’t built for long-term deployment—they’re designed to strike hard, move fast, and disappear just as quickly.