First question I have for you do you detect with the Threshold active in your Legend or do you just use the tones only, second thing do you want Bluetooth phones that go over your ear or in your ear or would you prefer to be able to hear what is going on around you while you are detecting, and trust me it will make a difference by the answers you provide
as Dig Dog stated you need to find a set of what ever you choose that are compatible with the Legend's wireless Bluetooth connection, which is aptX LL others will connect but not work as good if they do not utilize Codec aptX LL you will get some serious Lag when you sweep over a target
finding headphones, Earbuds, or Bone conduction Phones with aptX LL is hard because it is a older Bluetooth Connection, but can be done with enough searching
There are some Earbuds from a company called Home spot that are aptX compatible and from what everyone keeps telling me work good with the Legend, but if you are like myself and do not like having your ears covered or plugged then you will want something other than the Homespot earbuds.
I personall use a Neckband speaker that has earbuds incorporated into the neckband speaker, I also use a set of Bone Conduction headphones that work great as long as you do not detect with the threshold active in the Legend
here is the homespot earbuds
here is the Avantree Taurus which is the ones I prefer
Avantree Torus aptX Low Latency brings no audio delay for TV or movie watching. You can enjoy music at all times and be aware of your surroundings.
avantree.com
And here is a sett of Bone Conduction Phones that I use when not detecting with the threshold active in the Legend
Do you want to enjoy your favorite playlist and hear what’s happening around you at the same time? With Inductivv headphones, you can!
www.inductivv-store.com