RapidFit is an innovative, easy-to-install moulding option for remodeling projects. By fitting over existing moulding, RapidFit eliminates the need to remove old trim and reduces waste being put into landfills. It also covers untidy edges and gaps left by other improvement projects such as painting walls and installing flooring. RapidFit is manufactured from MDF and is primed and ready for paint. I LOVE this.