Inside Mount: LazBlinds Zebra Blinds's actual rail width is 1/8 inch narrower than the labeled size for a perfect fit inside your window frame. If your window is 28 inches wide, simply order the 28 inch blind for a smooth, custom look, no need to calculate deductions Outside Mount: For outside mount, we recommend choosing a blind width that is 2-4 inches wider than your window's outer frame. This ensures better coverage, effectively blocks side light, and offers a more polished look Installation Methods: We provide both strong 3M adhesive tape and hardware for drilled installation. You can freely choose between the "No-Drill" or "Drill" method based on your wall and needs, ideal for both renters and homeowners Cordless & Safe: The innovative cord free design offers a cleaner, more modern look while completely eliminating the safety hazards associated with cords, creating a safer environment for children and pets Zebra Blinds for Windows: Dual-layer fabric for daylight filtering and full night privacy. Perfect for living room, dining room, office, bedroom. Made of excellent Polyester. Good ventilation, anti-static, dust-proof and durable