The original fixture the thickness of drywall. Draw a line and Dado Lighting's will build a fixture around it. SimpleLineLED may be mounted in walls, ceilings, and across corners – from horizontal to vertical and every angle in between. No special framing is required due to its zero cavity, IC rated construction. 1.5", 2.5" and 3.0" widths. Order to any length. Can be field cut upon order for perfect fit.