*Click "See More" for Measuring Instructions* This product is cordless, child and pet-safe, and certified per WMCA "Best for Kids Program". The Light Filtering/Room Darkening fabric is from high-quality acrylic coated woven polyester, controls light, reduces glare and maintains privacy and insulation, and gently filters light. Attractive-looking fabrics are of the highest quality which gives you custom quality without the custom price. How to choose the right size for mounting inside the window frame: measure horizontally, along the top of your interior window frame. Round down to the nearest 1/4". How to choose the right size for mounting outside the window frame: measure horizontally, along the top of your window molding. Round down to the nearest 1/4". For optimal coverage, order 3" or more than the width of the window frame. *Please take note that the fabric panel is always 1-1/4" smaller than the final blind size that you order.