Hi. A couple of questions. How are the dimensions of the rectangular dampers determined? For the item "DD 8X10 Duct Damper 10x8", is the 8" the side of the damper with the screw in the picture or the other length of the damper? Also, does the damper come with the wingnut and handle to attach the handle and wingnut to the damper so it can adjust the damper position inside the hvac trunk? Thanks for the clarification!