A: It is an internal battery that never needs to be changed
A: Hello. Yes, the battery is built into the alarm and is activated by putting the alarm onto the bracket for the first time.
A: Hello. Pricing is set by Home Depot but like most things, it depends on supply and demand. If Home Depot has more of a supply of the single and 2 pack because there has been more demand of the 3 pack, they might put the single and 2 pack on sale temporarily. We'd recommend taking advantage of the sale.
A: Hello. Yes, this alarm should come with screws.
A: Hello. No, this alarm has an ionization smoke alarm sensor.
|Name||10 Year Worry-Free Smoke Detector, Lithium Battery Powered, Smoke Alarm||Firex Battery Operated Smoke Detector with Ionization and Photoelectric Dual Sensors||10 Year Worry-Free Sealed Battery Smoke Detector with Photoelectric Sensor||10 Year Worry-Free Sealed Battery Smoke Detector with Photoelectric Sensor and Voice Alarm|
|Alarm/Detector Features||10-Year Battery,Hush Feature,Tamper Resistant||Hush Feature,Tamper Resistant||10-Year Battery,Hush Feature,Tamper Resistant||10-Year Battery,Hush Feature,Tamper Resistant,Voice Alert|
|Alarm Sensor Type||Ionization||Dual-Sensor||Photoelectric||Photoelectric|
|Battery Type Required||.Built-In||9-volt||.Built-In||.Built-In|
|THD SO SKU||198092||1003095348||198092||198092|
|View Product||View Product||View Product||View Product|