The set in this article that I own is a special set for several reasons. It has a lot green present, it was made on Dec 12th 1968 (which still falls in the psychedelic years) and it is a catalog correct Rock Duo from the Ludwig catalog. Ludwig offered two factory catalog double bass sets; The Blue Note consisting of two 22" bass drums, 12,13,16,18 toms, matching jazzfest snare, canister throne and bongos. The Rock Duo is the smaller cousin featuring two 20” bass drums, 12,13,16 toms and a supraphonic 400 snare drum.