Stax SR-5 and SRD-6 adapter in very good condition.

These are electrostatic headphones, not the less expensive electret model from that era, which works on a different principle:  Search for Stax USA History for more info.

Purchased new in mid-1970s, used on and off for a few years, then stored away in early 1980s (went out of the country for several years).  They were working fine when stored away. 

However, I have long since sold off all of any sort of equipment that I could now use to test them.  

I did recently hook them up to a small class T headphone amp and them seemed ok.  To be truthful though, my hearing is a bit shot (bad tinnitus - too many rock concerts in the 60's and 70's).  

So as-is, what you see is what you get, no other guarantee or claims.  Feel free to ask questions and I will try to answer.

They are very comfortable.

Specifications:

Frequency Response: 30Hz to 25kHz

Maximum sound output level: 110dB

Note: for use with SRD-6 adapter

Shipping is free in the US lower 48 states only.  I will ship UPS Ground.