Koss Porta-Pros My Favorite Headphones

Koss Porta Pro:
https://www.amazon.com/Koss-155491-Porta-Headphones-Silver/dp/B00001P4ZH

Koss Lifetime Warranty:
https://www.koss.com/support/warranty-repair/

Zippered Case:
https://www.amazon.com/HIeGI-Koss-Portapro-Headphone-Carrying/dp/B00A7NC5Z8/ref=pd_sim_23_1?_encoding=UTF8&pd_rd_i=B00A7NC5Z8&pd_rd_r=24Z1PG8D0M5B8DVYV9HS&pd_rd_w=RTnpI&pd_rd_wg=LZJZQ&psc=1&refRID=24Z1PG8D0M5B8DVYV9HS

Sources:
https://www.amazon.com/gp/customer-reviews/RGRETC2NXR745/ref=cm_cr_dp_d_rvw_btm?ie=UTF8&ASIN=B00001P4ZH#wasThisHelpful
https://www.innerfidelity.com/images/KossPortaPro.pdf
https://www.innerfidelity.com/images/KossKSC75.pdf
https://www.innerfidelity.com/images/SennheiserHD600.pdf
https://www.innerfidelity.com/images/AudioTechnicaATHM50x.pdf