Key Features: Presented in a gift box Includes a card to help mum work out the code! Expertly engravedIf you\'d like to surprise mum with a fun unique gift, then this silver key ring engraved with the binary code would be the perfect fit! Used in mathematics and digital electronics a binary number is expressed in the binary numeral system represented by two symbols, usually zero (0) and one (1). So, to most passers-by it would look like an uncrackable code that only you and her understand. Engraved with the code to spell \'Mum\', you can both pretend it\'s your own secret language. Material: Pewter tag. Stainless steel split ringDimensions: Tag: 3 x 2.5cmRing: 2.4cm