When selling a house in Massachusetts, you must obtain a Certificate of Compliance from the fire department confirming that all smoke and CO alarms are less than ten years old, in working order, and interconnected with each other. When the inspector arrived at the Road House, he identified two units that were not compliant. Fortunately, he offered to come back in an hour and retest giving me enough time to drive to Home Depot, pick up replacements, return, and install them. Had he not been so accommodating, I would have had to schedule a second visit (minimum two-week booking delay) and pay an additional $50 inspection fee. Given that the fire department forced me to locate our backup batteries in the garage despite evidence demonstrating that they would be safer in the basement where I originally planned to install them, I was not expecting much lenience and was very thankful for it.