It creates a counterforce effect to help relieve ulnar wrist pain. Designed specifically for people experiencing ulnar sided wrist pain and mid-carpal instability. The Ulnar Booster™ is biomechanically correct, and can help this problem by realigning and stabilizing the carpal (wrist) bones while depressing the ulnar styloid. The splint straps combined with the foam boosting insert provides a boost of the ulnar carpus while depressing the ulnar head. This counterforce effect is helpful for conditions such as TFCC pathology, persistent ulnar sided wrist pain after wrist fracture, mid-carpal instability, and ECU tendonitis. When worn properly, the Ulnar Booster™ Wrist Splint should feel like a counterforce on the ulnar side of the wrist. Made of 1/16" (2mm) perforated neoprene with terry liner to keep skin cool and comfortable. Can be trimmed with scissors for a more personalized fit.Quantity: 1Color: BlackMaterial: Perforated neoprene with terry linerManufacturer: North Coast MedicalBrand: Comfort Cool®Options:X-Small - Left (NC68030-1) UPC: 768627001090X-Small - Right (NC68030-2) UPC: 768627001106Small - Left (NC68030-3) UPC: 768627001113Small - Right (NC68030-4) UPC: 768627001120Medium - Left (NC68030-5) UPC: 768627001137Medium - Right (NC68030-6) UPC: 768627001144Large - Left (NC68030-7) UPC: 768627001168Large - Right (NC68030-8) UPC: 768627001175Sizing Guide:X-Small: 4" to 5" (10-13 cm) Wrist CircumferenceSmall: 5" to 6.25" (13-16 cm) Wrist CircumferenceMedium: 6.25" to 7.25" (16-18 cm) Wrist CircumferenceLarge: 7.25" to 8.5" (18-22 cm) Wrist Circumference