Here is a Sonic blue lanyard, that comes with a round medallion. The medallion is likely acrylic clear coating over a metal back. It's still mint on the card here, which shows Sonic jumping while facing a mobile phone screen at the viewer. The phone says "Sonic Cafe".
What's that? It's the temporary 25th Anniversary celebration cafe set up in "Sweets Paradise", that included a Sonic themed menu, decorations, and clearly a buy-able souvenier type lanyard here. (Cafe photos appear on Gear too).