Purple marble disc with a purple sparkle metallic stamp. Purple on purple. Nice.
The Challenger OS™ is a slightly modified Challenger that features a "big bead" bottom rather than the small "bead" that typically adornes the bottom of the rim which makes the Challenger OS more O ver S table. The Rubber Blend refers to the micro beads of rubber that do not melt during the manufacturing process and leave the discs with a noticeable textured surface..