What you're looking at is Eldridge Cleaver's foray into the exciting world of genitalia-jeans-design. Yes, that's right, not only was he the spokesperson for the Black Panther Party and a renowned writer, he also found some time to enrich 70's couture-culture with a certain "je-ne-sais-quoi".
Tried to find some of these on Ebay, but no luck. Maybe some young and upcoming designer could reissue a modernized version? Some extra space for the balls would be nice.