Secret Message PenHandy and classic. Ideal for 6+ year olds who are keen on their secret or club messages. This very affordable item also has adult uses in recording and preserving passwords etc. Use the pen to write an invisible message on a piece of paper and the ultra violet torch to reveal the secret. Features: Special pen that writes with invisible ink that can only be revealed under ultra violet light The set includes a pair of refills as well as an ultra violet