[Reticuli2]

2dB tolerance is what the gal said on the phone to me.
 
The serial numbers on my repair pair are 214808 (L) and 214843 (R).

 

[JACONE]

If you have an old pair of Etys just send them in and upgrade which will cost you about $200. I had an old pair of the HF 3 that didn't work and sent them in.
I received a new pair of the ER-4PT for $200. I think this is a good deal. They sound amazing and much better than the HF3 0r 5.