This is an antique, late 19th to early 20th century, stained leaded glass window that has since been removed from its original architectural installment. The window features two roundels with a portrait of a man on each, likely historical figures who appear to be in 16th/17th century garb and hairstyle. The man with mustache and receding hairline is a likeness of the English playwright, William Shakespeare. Stained and leaded glass windows were popular in homes and public buildings, thus it is not particularly rare, per se. Shakespeare was particularly popular on these windows and generally placed in library or office settings. The estimate is based on actual recent past recorded auction sales of comparables. Retail 'asking prices' can be higher and vary.