Blinds width will 3/8" narrower for a snug internal installation. Actual blinds size is 21 5/8" W x 64" H. Choose the size SAME or CLOSEST to your window width for INSIDE mount. For Example, if your window width is 30 inch, order 30" or slightly less for internal installation. For OUTSIDE mount, we recommend order (2-4)inch wider than your window width for better coverage. Cordless Blinds for Windows: The cord-free design provides a clean, tangle-free look to the window and creates a safer environment for children and pets. Easy to raise up or lower down to control sunlight. Light Filtering: Switch between light filtering or room darkening by using the twisting wand. The tilt wand makes slats 180 degree turning to control light, block UV rays and provide privacy. Perfect for living room, family room, bedroom, bathroom. Easy to Install: Includes all the hardware you will need with simple instructions to make installation easy and convenient! Features mounting brackets designed for inside, outside, or ceiling installation. (Pls Note) For INSIDE mount, window frame should have at least 1 2/5” depth. Please read the picture to learn the light gap may happen on the window. Any questions please feel free to contact us: CustomerService@coprisma.com, and we will respond to you within 24 hours. LazBlinds Cordless 1" Vinyl Horizontal Mini Blinds, Light Filtering Blinds for Windows, Blinds and Shades for Windows