6 stars to 4. 7 stars, split between three packs and single units of this alarm, and over 335 reviews overall. The Kidde RF SM AC Est. $60 is similar, but is hard wired. Also known as the Kidde RF SM ACDC and the Kidde 1279 9999, one useful application is as a bridge between a pre existing hard wired, interconnected smoke alarm network and a new Kidde wireless interconnected network. Simply replace one of the existing hard wired smoke detectors with the Kidde RF SM AC and when a smoke detector on either network sounds, all will sound. The RF SM AC includes adapters that will allow this Kidde model to be used with most existing hard wired smoke detector networks. It's not been tested by any experts we deem to be credible, nor is there a ton of user feedback, but what is available is fairly positive including a 4. 8 star score based on nearly 50 reviews at Home Depot. If you live in an area that requires a 10 year sealed battery, the Kidde i9010 Est. $25 is worth considering.