Of all the cool gadgets in science fiction, one of the coolest is the memory-eraser stick that Will Smith and Tommy Lee Jones wield in the movie Men in Black. It is arguably one of the most powerful gadgets in science fiction, able to erase memories in a flash.

The bio-mechanical electro neural synapse transmission zero locator, but more commonly referred to as a Neuralyzer is the top-secret device used by MiB agents. It is one of the signature tools and considered agent standard issue. Also considered a standard issue equipment is the “Ray-Ban” sunglasses that deflect the light created by the neuralyzer.

The device is about the size of an average pen that gives a bright flash which erases the memories of the past hours, days, weeks, months or years, depending on the chosen settings. It first appeared in the first issue of the comic book series and has appeared in all three films, as well as the animated TV series. it will probably be featured in the upcoming spin-off of the Men in Black film series with Chris Hemsworth, Tessa Thompson, Liam Neeson among others.

“This is called a ‘neuralyzer’. A gift from some friends from out of town. The red eye here isolates and measures the electronic impulses in your brain. More specifically, the ones for memory.”

— Agent K describing the Neuralyzer to INS Agents.

In Men in Black 3, the 1969 variant of a Neuralyzer is shown to be roughly the size of an MRI machine. Similar in shape to the miniature Neuralyzer, the 1969 version is a cylindrical tube positioned in the center of a room and maintained by three MIB officials.