This cufflink contains shows both sides of a William The Conqueror Hammered penny. One side is on one cuff link and the other side is showing on the other. Both cuff links contain a full coin glued stongly onto the cufflink. Here's the description of the William I coin that is on this cuff link ...
"William I Two Stars Type penny struck by Grunal (ficticious) in Cardiff and representing a coin dating to 1074 - 1077."
Made from a modern die cut by a master craftsman to represent this type and hand struck from pewter. The die maker has used the name Grunal as the moneyer on the coin.