The product is a graded comic book titled Uncanny X-Men #221 from 1987, featuring the first appearance of Mr. Sinister. This vintage item belongs to the Copper Age of US Comics and was published by Marvel. As a key issue within the X-Men series, it is a sought-after collectible for fans of the superhero team. The comic book is in English and is a single unit sold individually. PSA 9.4.