{"product_id":"first-alert-9120b-smoke-detector-12-pack-hardwired-with-battery","title":"First Alert 9120B Smoke Detector 12-Pack - Hardwired with Battery","description":"\u003cp\u003eIn this review of the First Alert 9120B smoke detector 12-pack, the bottom line is straightforward: this kit is for homeowners and contractors who need reliable, hardwired protection across multiple rooms with minimal fuss. The single biggest reason to buy is the combination of hardwired interconnect capability and a battery backup that keeps monitoring during power outages, giving continuous protection for entire homes or job sites. Installation is designed to be quick and the detector focuses on fast-flaming fires thanks to its \u003cstrong\u003eionization sensor\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardwired with battery backup:\u003c\/strong\u003e Provides continuous AC power with a side-load battery compartment so the alarm remains active during outages for uninterrupted protection.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIonization sensing:\u003c\/strong\u003e Designed to detect fast-flaming fires that consume combustible materials rapidly, alerting occupants quickly with a loud alarm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInterconnectable system:\u003c\/strong\u003e Can be linked to compatible First Alert or BRK devices so every alarm sounds when smoke is detected across the home or site.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEasy installation:\u003c\/strong\u003e Universal mounting brackets and tamper-resistant locking brackets simplify mounting and reduce jobsite turnaround time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSimple operation:\u003c\/strong\u003e Single test\/silence button lets users verify function and silence nuisance alerts without complex controls.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePack of 12:\u003c\/strong\u003e Provides enough units to place alarms on each level and in bedrooms to meet recommended coverage without multiple purchases.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThis 12-pack is best suited for homeowners updating several alarms at once, new home builders, and contractors who want consistent, trusted detectors for multi-room coverage. The product appeals to people who prefer hardwired systems for reliability but also want the safety net of a \u003cstrong\u003ebattery backup\u003c\/strong\u003e during outages.\u003c\/p\u003e\n\n\u003cp\u003eIt is less ideal for users who need photoelectric sensors specifically for slow smoldering fires or those looking for wireless smart connectivity features beyond interconnectable hardwire systems. If you need a single replacement for an isolated room and prefer battery-only units, a single battery-powered alarm may be a simpler choice.\u003c\/p\u003e\n\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eReliable detection of fast-flaming fires with an ionization sensor and an 85-decibel alarm.\u003c\/li\u003e\n\u003cli\u003eHardwired design with battery backup ensures continuous monitoring even during power failures.\u003c\/li\u003e\n\u003cli\u003eInterconnect capability makes whole-home alerts possible when one unit detects smoke.\u003c\/li\u003e\n\u003cli\u003ePack of 12 offers strong value for full-home replacements or jobsite installs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSome buyers reported missing adapter cords or accessory pieces, so check contents before installation.\u003c\/li\u003e\n\u003cli\u003eIonization sensors are less sensitive to slow smoldering fires compared with photoelectric models.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eFirst Alert\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel series\u003c\/td\u003e\n\u003ctd\u003e9120B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower\u003c\/td\u003e\n\u003ctd\u003e120-Volt AC with battery backup\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSensor type\u003c\/td\u003e\n\u003ctd\u003eIonization sensor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInterconnect\u003c\/td\u003e\n\u003ctd\u003eUp to 18 compatible devices (inter-connectable)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAlarm output\u003c\/td\u003e\n\u003ctd\u003e85-decibel alarm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePack quantity\u003c\/td\u003e\n\u003ctd\u003e12 alarms\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe First Alert 9120B 12-pack is a practical, cost-effective choice for anyone replacing multiple alarms or outfitting a new build. Its hardwired design with battery backup and interconnect capability delivers dependable, whole-home protection, and the easy installation cuts jobsite time. For buyers prioritizing fast-flame detection and reliable operation across many rooms, it offers strong value.\u003c\/p\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eCan these alarms be interconnected?\u003c\/strong\u003e\u003cbr\u003eYes. They can connect to compatible First Alert or BRK devices so all connected alarms sound when one detects smoke.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDo they work during a power outage?\u003c\/strong\u003e\u003cbr\u003eYes. The 9120B includes a battery backup that keeps the alarm functional if AC power is lost.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this sensor good for all fire types?\u003c\/strong\u003e\u003cbr\u003eThe unit uses an ionization sensor optimized for fast-flaming fires; it is less sensitive to slow, smoldering fires compared with photoelectric sensors.\u003c\/p\u003e","brand":"First Alert","offers":[{"title":"Default Title","offer_id":48675498688731,"sku":"B07B4CDBLD","price":170.03,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/717OxpgXSmL._AC_SL1500_59818cc5-30cb-44bc-9b4d-0f0d5b7978aa.jpg?v=1778676223","url":"https:\/\/gearmusthave.com\/products\/first-alert-9120b-smoke-detector-12-pack-hardwired-with-battery","provider":"GearMustHave","version":"1.0","type":"link"}