The Exploiter is similar to the Metal Extractor, except it's armed with a Light Laser Tower on top and much thicker armor. It's as good as a normal extractor otherwise, except that it cannot produce metal while firing. It builds faster than a single LLT and extractor combined.
Useful for extracting metal from potentially dangerous areas, such as the frontline.
It's much tougher to destroy with a few artillery shells or missiles than a basic extractor. It can stay alive even under fire if constantly repaired, but don't count on it to fend off more than a handful of infantry bots or light tanks on its own.
Surrounding it with Dragon's Teeth can provide strong additional armor vs. direct-fire weapons.