XP wired 3.5mm backphone with 6.3mm jack adapter, foldable in three parts, very light, fits around the back of the head with volume control. 

Can be used with any detector that accepts 3.5mm or 6.3mm headphone jack.

Professional Minelab Underwater Headphones to be Used with the EQUINOX Series

Minelab Wireless Headphones come with regular Bluetooth technology, but also have enhanced, super-fast apt-X Low Latency technology for minimal time delay. Can also be connected directly to the detector's 3.5mm (1/8-inch) headphone socket for wired use, via the included aux cable.

Compatible with the Equinox series and Vanquish 540.

Nokta Makro 2.4GHz Wireless Headphones - (Green Edition).

Waterproof Wired Headphones from Nokta Makro. 

Use with Headphones that have a Standard 1/4" Jack Connector. 

The XP WS Audio Wireless Headphones aka Backphones are for use with the XP ORX Gold Detector. They provide loud and clear audio making it easy to hear those faint signals when prospecting for gold nuggets in Africa.

Garrett’s Z-Lynk Wireless System offers all the benefits of using your favorite headphones, along with the freedom from being tethered to your metal detector.

Allows land-use headphones with a 1/4” male jack to be used with the Garrett ATX, AT Gold, AT Pro, Infinium and Sea Hunter models. (Not intended for submerged use.)

Garrett ClearSound Easy Stow Headphones

• Includes in-line volume control

• For use with Garrett ATX, AT Gold, AT Pro, Infinum LS, and Sea Hunter Mark II metal detectors
• Padded ear cups