This shed window is 18″ wide and 23″ tall. The bottom half has a screen and the top half is fixed in place.. If you are installing vinyl or metal siding we recommend the J-lap flange. Both windows come with a 1″ metal nailing flange. Bottom half opens for ventilation, has a removable screen and locks into 3 different opening positions. This window has many other uses beyond a simple outdoor storage shed. You could use this for a chicken coop, deer stand or blind, dog kennel, outhouse, man cave, or any other backyard structure that needs a simple and effective window. Please see our other listings for different colors and flanges.