This item is PRE-CURVED to fit HALF round shaped arches ONLY (will NOT fit eyebrow type arches). Diameter sizes match inner window jamb sizes.
For interior and exterior use - will not warp, rot or crack when exposed to high moisture
Can be installed with normal woodworking tools.
Material is flexible polyurethane resin - only recommended for painting applications but can be stained with a gel based stain
See available diameter sizes above. CAN NOT force this pre-curved material to go straight.