MOUNT TYPES: Inside mounted shades will have a deduction taken of approximately 1/4" to ensure a proper fit inside the window frame.Inside mounted shades require a minimum frame depth of 2.5inch for secure installation. If your window frame depth is less than 2.5inch please select outside mount.Outside mounted shades should be ordered with the exact width of the area you wish to cover. Outside mounts are often used when there is not sufficient frame depth for inside mounting.Our shades come with all mounting hardware, and mounting hardware for both inside mount and outside mountINSIDE MOUNT MEASUREMENT: Step 1.Measure the inside frame width at three locations-the top,middle,and bottom. Record the smallest of the 3 measurements and use that number deduct 1/4inch as your inside width when ordering.Step 2. Measure the height at 3 locations-the left,middle,and right side. Record the smallest of the 3 measurements and use the number as your inside width when ordering.OUTSIDE MOUNT MEASUREMENT: Step 1. Measure the outside frame width adding 6-10inch to be the outside mount width.Step 2. Measure the outside frame length adding 5-10inch to be the outside mount length. The overlap it recommended to allow appropriate coverage and avoid any light gaps.Type: Aluminum Horizontal Window Blinds.Feature: Thermal Blackout Waterproof UV ProtectionMaterial: AluminumInstallation: All Mounting Hardware Included.