Preparation for size selection: Measure window length, width multiple times at different locations Installation requirements: Internal Installation: The depth of the window frame needs to be greater than 2". Blind width needs to be at least 1/4" less than the window width. External Installation: Blind width needs to be at least 4" wider than the window width. Blind length needs to be at least 8" longer than window length, to cover the entire window. Package Included: Roller Shade Blinds x 1. Mounting accessories x 1. Installation Manual x 1. More information about our roller blinds: Blackout covering material can effectively protect your privacy, isolate the heat, and balance the temperature by darkening room. If you are troubled by UV rays damage furniture, please choose our roller blind without hesitation. Thick fabric can block some external noise, is good for deeper and longer sleepers. Cordless design, which is safer for children and pets. You'd better wipe it with a wet cloth or cold water when it gets dirty. Suitable for kitchen, bathroom, office, bedroom, garage, study, family room, nursery, and so on