The 13 "DD (33 cm) M@rs MD Discovery coil has the optimal dimensions for universal research. It is 100% waterproof and protected from electromagnetic interference. This is specific for Rutus Alter 71 metal detectors. It is a very good coil. balanced, lightweight and reliable for a wide range of search tasks. Detects targets at considerably greater depth and provides a wider scan than standard coils. It has three frequencies 3.5 kHz low, 7.5 kHz medium, or high at 18.75 kHz which work individually, they can be varied with a 9 volt battery by resting it on the poles as seen in the photo below.
Features:
• Round DD coil.
• 100% waterproof.
• Protection against electrical interference.
• Screw connector.
Package Includes: Free Coil Cover, Connector Protective Cap and Coil Retaining Bolt.