Zildjian Rock Crash 18" Crash Cymbal 1850g 1981-1992 (“CO.” Stamp)Notes approx 1850 grams The CO stamps were the last unique signatures on Zildjian models until the company introduced their laser engraving system in 1994. They take their name from the CO in Zildjian CO whereas prior models read Zildjian Co. A Zildjian Rock Crash 18" Crash Cymbal 1850g 1981 1992 (CO. Stamp) in Very Good condition! At Evolution Music, we attempt to highlight cosmetic defects (if any) by picturing every angle of every piece of gear so