- "Oh, my. A radiation-controlled proto-environment housed in a vacuum-sealed, mechanical exoskeleton contained in a spring-loaded two-millimeter disc."
- —Querl Dox[src]
The suit was designed by Lena Luthor to protect Supergirl from the Kryptonite-ridden atmosphere. Once the Earth was purified of the substance, Supergirl occasionally used the suit in battle in certain situations which required extra protection.
After Mercy and Otis Graves released Kryptonite into the Earth's atmosphere, Kara Danvers/Supergirl began dying from the exposure. Upon learning of the situation, Lena Luthor arrived at the D.E.O. and gave Supergirl a suit she designed to protect her until they could somehow detoxify the atmosphere. Once Kara regained consciousness, she began panicking and had trouble breathing until Alex Danvers calmed her down. Alex explained the situation and ordered Kara not to exert herself, since the suit only had enough energy to filter out the Kryptonite.
Later, during Kopy's attack on the National City Police Department Precinct, Kara tried to use the suit to fight off his army. However, Kara was eventually overwhelmed and the suit took too many hits. As a result of the damage, the suit began faltering in filtering out the Kryptonite and Kara nearly died. Fortunately, J'onn J'onzz saved her while Brainiac 5 fixed the suit.
The next day, Kara used the suit to stop a mind-controlled Kopy and Hellgrammite from attacking a carnival. Kara was successful, but not before Otis and Mercy ambushed her. However, Lena and Brainy managed to purify all the Kryptonite from the atmosphere, allowing Kara to remove her suit and use her powers.
- Kryptonite filtration: The suit is designed to filter out the Kryptonite that was flooded into the atmosphere. However at the cost of durability, as Kara can be killed in the suit if it sustains too much damage.
- HUD display: A HUD was built into the suit to give Kara readings on the suit's current state. It was used when she was beaten down during her first outing as Supergirl while in the suit.
- Space survivability: The suit allows Kara to breathe in outer space due to its filtration system.
- Suit storage: The suit can now be hidden inside Kara's usual suit. Using her symbol as a release mechanism.
- Claustrophobic: The suit is an extremely tight, enclosed space, to the point where it triggered Kara's claustrophobia when she first woke up in it, forcing Alex to calm her down from a panic attack.
Behind the scenes
- This protective suit is a possible reference to Superman's Kryptonite suit.
- The suit also has the same colors and design as Lex Luthor's Superman suit from DC Rebirth.
- The suit's plot line was used to allow Melissa Benoist to continue her time on Broadway, as she didn't have to be in the suit the entire time when the show was being filmed.
- Kara wearing this suit is playable as "Multiverse Armored Supergirl" in the Injustice 2 Mobile game. In-game, the face area can turn clear and allow her to use heat vision in some attacks.