Vinyl Inside Mount ONLY. For better internal installation, blinds width will 2/5" narrower. Actual Blinds Size is 19 3/5" W x 36" H, the unique spring rod can extend 1 inch in total, allow the blind to fit for window width 19.7-20.6 inch, blind height can adjust from 0" to 36". (Pls Note) Minimum 1 1/5" depth of window frame required for inside mount. No Drill Blinds: LazBlinds patented technology No Tools-No Drill system allow it no need to drill any holes on your window frame, perfect for Renter, Landlord, and Home Buyer. Easy to Install in 30 seconds. Cordless Blinds for Windows: Simply hold the bottom rail to lift or lower the blind down. No more exposed dangling cords. Providing a more modern and cleaner appearance to every room and a safe environment for home with pets and kids. 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. Fit All Kinds of Walls, like woodiness metope, tile marble, concrete wall and rough tile. Won’t Fall Off: The Metal Top Rail can afford maximum 30kg, absolutely safe to use.