These are very rare, almost unheard of headphones from the '70s. They sound just as good as my Sennheisers, I have tested them today and they are still fully working, I was impressed. I have the box and the manual though both are a little tatty.
If anyone is interested I can take some photos and upload, discuss a price etc. NB the photo here is just one I found on the web. Mine still have a little tag attached saying "Ear head pad composition leatherette", not present in the photo. I'm in the UK but will post wherever you like.
Type: Back Electret
Frequency Response: 20 - 20,000 Hz
Impedance: 1,000 ohm , 300ohm , 8 ohm
Sensitivity: 104 dB / 1 V ( 8 ohm )
Distortion: Less than 0.5 % ( 400 Hz )
Cord: 2.5 m
Wight: 160 g ( Without Cord )
See here for a few further details on the cans:
Keywords: Toshiba electret condenser headphones Aurex HR-710