Chase Covers: All chase covers are custom made to fit the top of your chimney. Chimney chase covers will typically require a service call to your home for us to take measurements, and will require payment in full before fabrication can begin because they are custom made. If you plan on installing your chase cover yourself & just want us to build the chase cover for you according to your dimensions we can do that as well. However, if we make a chimney chase cover to your dimensions, and it does not fit your are stuck with it. If we come take measurements, we are responsible for it fitting.