Thermoskin Hyperextension Elbow features X cross hook and loop locking straps. Combining these straps with the medial and lateral hinges provides a bracing mechanism which stops hyperextension at zero degrees. This support may be suitable for those suffering from medial elbow instability or elbow hyperextension ailments. Quantity: 1 Color: Black Manufacturer: Thermoskin Indications: Provides a bracing mechanism which stops hyperextension at zero degrees. May be suitable for those suffering from medial elbow instability or elbow hyperextension ailments. Options: Small (83189) UPC: 609580831891 Medium (84189) UPC: 609580841890 Large (85189) UPC: 609580851899 X-Large (86189) UPC: 609580861898 XX-Large (87189) UPC: 609580871897 Sizing Guide: Small: 9in - 10 1/4in (23-26cm) Medium: 10 1/2in - 11 3/4in (27-30cm) Large: 12in - 13 3/4in (27-30cm) X-Large: 14in - 15 3/4in (36-40 cm) XX-Large: 16in -17 3/4in (41-45 cm)