Use AtlasIED 195-812 protective enclosure for recessed mounting of 840-812A clock/speaker baffle. The 195-812 has 12 knockouts (four on both top and bottom, two at each end). Constructed of 20-gauge CRS and are heavily undercoated to prevent mechanical resonances. Unit contains a compartment divider to separate high and low voltage wiring. Finished with an epoxy coating.