4-1/8" Face Focal Point Quick Clip Acropolis Crown Moulding, Allows For Easy Professional Installation Using The Quick Clip Mounting Brackets, This Quick Clip Moulding Installation System Features: Quick & Easy Installation, No Need To Find Studs, No Nail Holes To Patch On Molding Once Installed, Sturdy Light Weight Molding, Uses Focal Point Corner & Connector Blocks To Eliminate The Need To Miter Corners, Simply Mount The Quick Clip Mounting Brackets, Sold Separately, Against The Ceiling & Spaced Every 12 Inches, Then Install Corner Blocks & Measure The Length Between The Blocks & Cut The Molding 1/8" Longer Than Your Measurement, Snap & Lightly Tap The Molding Into Place & Your Done.