Delta Blinds Supply Custom-Made, Premium Real Wood Horizontal Window Blinds, 2 Inch Slats, Inside Mount, Dark Mahogany, Inside Window Size: 66.5" W x 48" L WINDOW SIZE SELECTED: 66.5"W x 48"L, Inside Mount. Actual blind width is 66 in. Fits inside a window frame that is 66.5 in. wide. The valance will be exactly 66.5 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 INSTALLTION: Instructions and hardware are included. Estimated duration: 5 to 15 minutes per window. QUALITY: Material is made from 100% kiln dried Basswood, a light-weight and durable hardwood from the northern United States. The material is warp-resistent, best suited for non-humid rooms. CERTIFICATIONS: Greenguard Air Control and Greenguard Schools & Children. 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.