Sonar

The Sonar legs are produced by Neuropa. They provide underground vision and decent visual radius, while being defensively weak.

Official Description
"Sonar Legs emit powerful sonar waves that are designed to eliminate the fog-of-war. Unlike Recon Legs, Combots outfitted with Sonar Legs are able to reveal the Underground topography if they are located on the Surface layer. The Sonar Legs will also expose some of the Surface layer, although they are nowhere near as good as Recon Legs. Furthermore, Sonar Legs have a relatively weak defensive capability making them extremely vulnerable to enemy attack."

Tactics
This bot part becomes a powerful tool to scan for enemy underground buildings in a way that is more viable than building Recon Poles or a Recon Salvo Railgun.

A good strategy is having a Combot also equipped with a Camo Torso, making it a hidden scout.