It’s not hard to imagine a time when someone might need to protect themselves against a violent attacker. According to Seth Froom, inventor of the Yellow Jacket iPhone case, approximately 1.3 million Americans were victims of violent crimes in 2011. As the CTO of the company that makes “the world’s only stun gun smartphone case,” that's an FBI statistic the inventor knows well. 

The idea for the device came after Froom was victimized in a violent robbery. While he had firearms in the house, “in the moment [they] did nothing to protect me,” Froom said. He also owned a traditional stun gun, coincidentally in the shape of a cell phone, but he never carried the device as it was bulky and inconvenient. So the idea was born: a non-lethal protection device he could carry that was conveniently attached to his cell phone.

The Yellow Jacket packs a whopping 650 thousand volts in a 14 oz. iPhone case. Currently, it's only available for iPhone 4/4s models, but Yellow Jacket is debuting its iPhone 5/5s case at the 2014 International CES, ready for purchase in February. Cases for the Samsung Galaxy S4 and other devices are planned for summer 2014.

The Yellow Jacket might be one of the most interesting devices at CES. While most devices that are raved about are entertainment-related -- think Samsung’s or LG’s curved UHD televisions, or wearable tech, like smart watches and wellness trackers -- Yellow Jacket may be the only personal protection device at the trade show giant. Several other exhibitors are demoing smartphone case battery packs, but this is the only one that provides a “sting” as well.

But the case can power an iPhone when an extra charge is needed. The Yellow Jacket provides up to an 24 hours of additional battery life without affecting the stun gun’s operation. That’s because the stun gun has a separate battery to prevent it from failing when needed. A full charge takes just four hours.

But that’s not the main focus for Froom and CEO Sean Simone. “We are committed to branding the Yellow Jacket case as a successful means of protection,” Simone said. According to research conducted by Yellow Jacket, “approximately 13 percent of women living in the United States will be attacked at one point in their lifetime,” Froom said. 

Concerns over user safety came up when designing the case. To prevent accidental self-shock, Yellow Jacket has two safety features that deter user error. First, a safety switch must be engaged before the trigger can be activated; second, there is a physical barrier in the form of a safety cap that prevents electrode-to-skin contact, which must be flipped down.

While this can prevent accidental discharge, it could take up crucial time during an attack. Yellow Jacket recommends education about self-defense and its equipment for all customers. Its website offers Krav Maga schools as a source for self-defense education. “Violent crimes leave a victim traumatized,” Froom said, speaking from his experience.