100% Polyester 【Excellent Material】：AOSKY cordless roller shades made of 100% polyester material fabrics with reinforce thermal insulated coating, feeling soft and smooth. No burrs, strong wear resistance, and easy to clean.Our blackout blinds block 100% of sunlight and UV rays. The thermal backing reduces the loss of room heat and against cold through the windows in winter and summer, helping to reduce your energy bills. 【New Innovative Design】: The cordless design is safer for kids and pets. The cordless roller blinds are more convenient than corded roller blinds. Built-in the robust spring-loaded mechanism, which has passed 5,000 times usual lifting or pulling down tests for each blind, You can stop the shade wherever you want smoothly. Open the roller blind, pull it to the place; Shut the roller blind, you can gently pull the buckle, and the roller blind would automatically close. 【How to choose right size】：To make sure to cover the entire window, outside mount shades need to be 4 inches wider than windows wide. If your windows width is 30", order size 34" would be okay for outside mount；If your windows are 30" wide, order 30" or slightly less for internal installation. Don't worry window blinds height,it can adjust from 0" to 72". （Pls Note）：Fabric width will be 1" narrower than the size of the shade. 【Convenient Installation】：Our product comes with an installation package that includes installation instructions, installation screws, metal brackets, to help you install the product quickly.（In addition to the paper instructions included in the package, our installation video will guide you through the installation. If you encounter any problems, please contact us in the first instance and we will give you a satisfactory solution） 【How to adjust the rebound position and rebound speed of roller blinds？】： Adjusting the rebound speed: open the right side cover and adjust the screw clockwise to make the rebound speed slower and counterclockwise to make it faster. Adjusting the rebound position: open the left hood and adjust the screw counterclockwise to stop the roller blinds in the desired position and return to this position when contracting the roller shades. 【Package Include】Our curtain fabric includes a roller blind, a set of accessories. Note: If you are missing accessories or have any problems, please contact us and we will provide you with a satisfactory solution within 24 hours.