Rectangular Joints and Reinforcements are setup per standard length. The standard length is the centerline length of an item, including fittings. For example; a transition 36 inches in length will use the 36 inch table for duct standards.
Use the Global Edit button to modify the defaults and the Copy From button to copy setup information from one standard length to another.
Alternates allow you to make alternate joints, reinforcements, and sealants available within the pressure class.