QMX Firefly Coaster Set Firefly coasters are officially Licensed by Quantum Mechanix. Coasters feature the Blue Sun Logo, Serenity Nose Art, Star of the Independents, and Firefly Logo. Each Firefly coaster measures 3.5" Made from metal wrapped over a non-slip cork backing to make sure it stays in place. Firefly Coasters come with a round metal tin holder