Compatible headphone impedance and sensitivity for GPX MW3847?

I would like to get decent headphones for my MW3847 as I damaged the cord for the earbuds and the last two no-name cheapo earbuds had inadequate.

The manual (and first request to their tech support) offer no specs...at all.

I repeated my inquiry - maybe they misunderstood what I wanted.

I hoped to find impedance and power output to help select compatible headphones. Since those specs are unpublished, I doubt anyone here knows, but you could share what brand of headphones were satisfactory, and perhaps the headphone specs.

Worst case I guess I could just get the highest sensitivity ones I can find. I think higher impedance may be easier to drive...