The AF31SL is a panel board front trim from the A Series, sized 31-1/2" x 20" and specified for surface mounting. This is the trim panel that covers the front of the enclosure — the part the panel builder cuts the opening for and fastens after the interior gear is wired.
Integration Note
Surface mount means the trim fastens directly to the panel board enclosure front, not recessed into a cutout. The 31-1/2" x 20" dimension is the trim's overall size — the actual panel opening will be smaller, sized per the enclosure manufacturer's cutout template. Part of the A Series family, so it shares the same trim profile and fastener pattern as other A Series components on the same board.