I have tried several different earbuds with my Legend the ones that seem to work the best are Black Shark I think they are T1s, they are 35 Ms also the Black Shark T4's
but be aware if you use the threshold on the Legend they do not work that good at all
I have used Tozo N9's, Tozo T10's and several others but like I said all the earbuds I have tried with the Legend does not work good if you use the threshold
if you do not use the threshold all I mentioned, all of them work good, just not good when using the threshold
some others you might want to check out are made by a company called Inductivv, I have been using some of them and they work good also, they are a Bone Conductive headphones, bone conductive headphones do not go in your ears but lay on a spot by your ear which leaves your ears open so you can hear other things that is going on around you