The secret compartment in the blade's hilt.
Built with a sword-like shape, these blades used by Lady Qi'ra were capable of emitting electrical charges which, upon contact, allowed them to effectively repel and resist clashing with a lightsaber without them being damaged. The blade itself was black, while the hilt was gold. There was a small compartment at the end of the hilt that could release a series of small grenades. The two swords could also unite the end of their hilts to create a larger double-bladed melee weapon.
Qi'ra unites both blades to fight Vader.
After receiving extensive training on Teräs Käsi and Sith combat by her master Maul, Qi'ra used electric blades for melee combat as the head of the criminal syndicate Crimson Dawn.
During the Auction for Han Solo conducted by Qi'ra aboard the Crimson Dawn flagship Vermillion, the Dark Lord of the Sith Darth Vader interrupted the auction by claiming that he had more right over the carbonite block that contained the smuggler Han Solo than Jabba the Hutt. After the two reached an agreement to deliver Solo to Vader, Qi'ra said that she still required to be paid back and mocked the Empire for being too cheap when Vader refused to do so. This prompted the Sith Lord to ignite his lightsaber and attack Qi'ra, and she responded by baring her own blades and engaging in a brief duel with Vader.
While Lady Qi'ra dueled Vader, the Sith Lord remarked on her training before starting to Force choke her, to which Qi'ra responded by opening the compartment on the hilt of one of her blades and unleashing small grenades on Vader. The attempt was ineffective however, as Vader used the Force to avoid the explosion. Qi'ra then proceeded to unite both of her blades and attack Vader with the double-bladed weapon before the Sith Lord used the Force to push Qi'ra back, causing her to drop her blades and fall to the ground. After her defeat, Qi'ra was spared from being killed by Vader as the Sith Lord became distracted by the arrival of the rebel Luke Skywalker.
Qi'ra's electro swords first appeared in the Marvel Comics comic mini-series and crossover event Star Wars: War of the Bounty Hunters, created by comic writer Charles Soule and illustrated by Luke Ross.