Nylon outer material is lined with a plush foam for exceptional patient comfort/ Dual stays support both the palmer surface of the wrist and the extensor surface of the thumb/ Thumb support adjusts with hook-and-loop closure/ Three forearm straps secure with loop lock closure for a high level of compression/ Left, Medium. 8" (20.3 cm) L, 6-1/2-8" (16.5-20.3 cm)Circumference.