Hybrid Test Note with "OPTIKS" feature produced by De La Rue Currency with portrait of Sir Isaac Newton in very beautiful colored intaglio design on real banknote paper. The note is a so-called hybrid note (window banknote) which is made of cotton but has a window in paper with a holographic foil. When the window is held against the light different features can be visible. At this example a repeating design of an apple is visible in the window. This OPTIKS feature is used on many different banknotes in different countries today. The note has a serial number AA333333. Condition: UNC.