Universal Design: The AC bracket for window is compatible with most brand window units 5,000 to 24,000 BTU , and supports up to 165 lbs. Wall Thickness: Its wall thickness from 2" to 15.2", exclusive built-in bubble level to correct mounting slope position. The bracket should be installed with a slight tilt down for condensate draining purpose. Indoor installation: Easy breezy install, without exterior work, no drilling of outside wall or siding, just drilling into window sill, less harm for windows and the outside wall. Safety indoor installation, necessary hardware and instruction sheet are included in the package for your convenience. Durable Material: Heavy duty steel constructed finish with a nice powder coating surface treatment, allows the bracket to survive all weather elements, designed for long term outdoor service. Complete accessoriesAll required accessories are provided. Built-in leveling instrument assures proper mounting angle, and 3 different kinds of spacer to adjust the height.