If you are looking for specific technical data rather than a model number, "218" sometimes appears in the following contexts:
is designed for treasure hunters and archaeologists to detect buried items like coins, jewelry, treasure caches, and underground structures such as tunnels or caves. : OKM 218
Honestly, a company with credibility and the detectors are something very special. Great device, precise and easy to work with. If you are looking for specific technical data
OKM Detectors: Detectors and 3D Ground Scanners Made in Germany OKM 218
: While specific maximum depth for this model varies by soil, OKM's premium technology is generally capable of detecting objects down to 82 feet (25 meters) . Expert and User Perspectives