It's “@.” Email Sign Cufflinks It's the most important sign in information age. It's in email and twitter. It's almost everywhere on the internet. It's communication. It is also a pair of cufflinks, made of rhodium plated base metal. Two types are available. One is flat face with black enamel wrapping the silver a in the center, the other with silver hollow frame. Approximately it will measure 3/4 by 3/4 inch.