No, this is the KN-COEG-3; the KN-COPP-3 unit can be seen below with either a rechargeable battery back-up or a battery back-up. I hope this helps.

Yes, this detector is able to detect natural gas leaks as well. Hope this helps.

The Kidde CO alarms are meant for residential home use. Depending on what you have in your shop and where it is located, solvents, dust/workworking, chemicals, etc could contaminate your alarm causing it to false alarm. Whether the CO alarm is a plug in model or a hardwire unit, it can still become contaminated by fumes & dust from the shop. CO alarms are sensitive to ambient temperature changes as well.

The sensor in these units is the reason they need to be replaced after 7 years. The sensors reliability degrades over time and the 7 year life span allows the unit to be replaced before this happens. For your safety, just go ahead and replace the unit.