Comfort Cool Wrist/Thumb CMC Splint, Size: M, LeftLonger length thumb 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.Supports the wrist and thumb for combined conditions such as arthritis, CTS, de Quervain’ s, tendinitis, joint instabilities and post-surgical repair of the wrist and thumb. The special pull-through wrist strap requires less hand manipulation, making it easy to adjust and fasten the splint. Neoloop? strap material provides extra support and compression around the wrist. Hand or machine wash and air dry. To size, measure circumference of MP joints at the distal palmar crease. Sizes in left or right. SizeToddler: Palm circumference 4½ “ to 5½ “ (11 to 14cm)Youth: Palm circumference 5½ “ to 6½ “ (14 to 17cm)Small: Palm circumference 6“ to 7“ (15 to 18cm)Small Plus: Palm circumference 6½ “ to 7¼ “ (17 to 18cm)Medium: Palm circumference 7“ to 8“ (18 to 20cm)Medium Plus: Palm circumference 7?“ to 8¼ “ (20 to 21cm)Large: Palm circumference 8“ to 9“ (20 to 23cm)Large Plus: Palm circumference 8¼ “ to 9½ “ (21 to 24cm)X-Large: Palm circumference 9“ to 10“ (23 to 25cm) Product photo may not exactly match the product offered for sale. Please refer to the product description.