KOSS PRO 4AAA Professional Headphones 1976 ULTRA RARE NEAR MINT L@@K FREE P+P.!!
In 1976, Koss introduced the Pro/4AAA. Building off of the Pro/4AA’s iconic sound, the Pro/4AAA incorporated a number of new design features. The most notable of these features was the headphone’s Direct Contour Pneumalite ear cushions.