Comfort Cool Wrist & Thumb CMC Splint. The Comfort Cool Wrist & Thumb CMC Splint provides additional support for the wrist while allowing full finger function. Unique one piece wraparound supports feature a contoured strap that wraps around the thumb CMC joint and the first metacarpal for direct joint support. Reinforced stitching allows the splint to be trimmed below the thumb MP joint. Made of thin, 1/16 (1.6mm) perforated neoprene with a terrycloth liner that helps keep skin cool and comfortable. Latex free.