Fixed Lateral Thoracic Supports. The aluminum brackets combine high strength and low weight while providing good durability. Flat Pads are standard with the fixed brackets. (curved pads are a n/c option) Standard brackets have a 5" anterior / posterior measrement and fit backs up to 3"" overall thickness. Brackets are convertible to Summer/ Winter with the addition of Receiver Brackets. Flush mount will be sent as standard. See Hardware Sections C 7 and D 7 for components.