I am not the original owner, bought both used from Headfi classified to try them out
Both in good used conditions

-HD 660S only comes with the 6.35 millimeter to 3.5 millimeter adaptor cable ( NO 4.4mm cable)

company information on HD 660S
https://www.sennheiser-hearing.com/en-US/p/hd-660s/

-ATH-R70x
https://www.audio-technica.com/en-us/ath-r70x

Reason forsale- looking to move these along and try others
Price is for both and includes shipping to lower 48 and PayPal fees
Stands are NOT included
selling as a bundle

Any questions, please PM me
Thank you and Happy Listening!!!