Delta Blinds Supply Custom-Made, Faux Wood Horizontal Window Blinds, 2 Inch Slats, Inside Mount, Chestnut (Medium Brown,) Inside Window Size: 40.5" W x 64" L WINDOW SIZE SELECTED: 40.5"W x 64"L, Inside Mount. Actual blind width is 40 in. Fits inside a window frame that is 40.5 in. wide. The valance will be exactly 40.5 in. wide. EASY MEASURING INSTRUCTIONS: To ensure you receive the correct size blinds please only use our measuring instructions for guidance (second photo on this page.) FAST & SIMPLE INSTALLATION: Instructions and hardware are included. Estimated duration: 5 to 15 minutes per window QUALITY: Material is made out of a poly-vinyl blend which is resistant to humidity and temperature change, perfect for kitchens and bathrooms. CERTIFICATIONS: Greenguard Air Quality and Greenguard Children & Schools. The Greenguard Certification program "gives assurance that products designed for use indoor spaces meet strict chemical emissions limits, which contribute to the creation of healthier interiors." VARIABLE LIGHT CONTROL & FUNCTION: You can modify the amount and quality of light entering a room, even when a window blind is fully open or closed. Blinds provide variable light control via their adjustable slats. The functionality has a smooth operation, high load capacity from heavy-duty components, and crash-proof cordlock.