Bluetooth relay strip and its 12V -> 5V power adaptor (which is attached to 12V via a small accessory fuse panel not seen here). This all fits snugly to the left of the main relays. Garage door functionality is added in the easiest possible way. A garage door opener from Home Depot has one of its buttons wired to one of the relays on the strip. The range on this is MUCH greater than adding Bluetooth to the garage door system itself.