We have been renovating our 14-year-old home that has concrete walls. Our electrician recommended that we find a step light fitting that fitted the current cut-out, as it would be challenging to fit something of a different size. It was easy to find a suitable light fitting as The Lighting Outlet website has the cut-out sizes listed (plus lots of other useful information). The lights look good installed, and our electrician had no issues fitting (we only need to update the drivers).