The 1989 Pro Set Chuck Knoll Error Card #355 is a highly sought-after collectible in the sports trading card market. Features the error in the text on back "One of only three". It was corrected to "One of only two". The card depicts Chuck Knoll, a legendary coach for the Pittsburgh Steelers in the National Football League, adding to its value and appeal to fans and collectors alike. With its original card stock material and error feature, this unique piece of memorabilia is a must-have for any football card enthusiast.