Scouter

A Scouter is a compact device worn over one ear with a translucent colored lens that covers one eye. According to Akira Toriyama, soldiers in Frieza's army can have Scouters custom-made to fit their particular ear shape, and the lens color can be selected based on the user's visual preferences or the peculiarities of their alien eyes. Common lens colors include green, red, blue, and purple.

The Scouter's primary function is reading and displaying power levels, translating a target's fighting strength into a numerical value. Beyond power measurement, Scouters also function as communication devices, allowing soldiers to relay information across vast distances, and they contain targeting systems and data lookup capabilities. The technology was originally developed by the Tuffles and later refined by Kikono, a scientist within Frieza's organization.

Scouters have a critical flaw: they cannot account for warriors who can suppress or rapidly increase their power levels. When a reading exceeds the device's maximum threshold, the Scouter overloads and explodes. This happened repeatedly throughout the Namek Saga as the Z Fighters demonstrated power far beyond what Frieza's soldiers expected.

The Scouter's introduction at the beginning of Dragon Ball Z fundamentally changed how power was discussed in the series. When Raditz arrived on Earth, his Scouter provided the first concrete numerical measurements of characters' fighting strength, establishing the iconic power level system. Readings such as Goku's 416 and Piccolo's 408 (with weighted clothing) gave fans a quantifiable way to compare fighters for the first time.

The Scouter's most memorable moment came on Planet Namek, when Vegeta and others from Frieza's army relied on their devices to gauge threats. The repeated shattering of Scouters became a visual shorthand for encounters with power beyond comprehension. Zarbon, Dodoria, the Ginyu Force, and even Frieza himself used Scouters at various points, with the devices consistently failing to capture the rapidly escalating power of the Z Fighters.

After the Namek Saga, Scouters largely disappeared from the main story as the ability to sense ki made them redundant. However, they continued to appear in flashbacks, in Frieza Force contexts during Dragon Ball Super (particularly in the Broly film and Resurrection 'F'), and as cosmetic accessories in numerous video games. Bulma also studied Scouter technology and incorporated some of its principles into her own inventions.