Low profile design. Tamperproof 10 year sealed lithium powercell photoelectric smoke alarm with silence feature. Tamper resistant - Locks alarm to mounting bracket to prevent removal of alarm. 10-Year Lithium Power-10 years of continuous protection. No battery change required. Provides audible notice when alarm has reached its end of life. Photoelectric smoke sensing technology Silence feature Tamper Resistant-Locks alarm to mounting bracket to prevent removal of battery and/or alarm. Perfect for apartment, dormitory or hotel applications. 10-Years Limited Warranty Model: PR710B Alarm Dimensions: 5.2”Dia. x 1.13”H Weight: 6.0 oz Operating Voltage: 3V Lithium Power Cell Temperature Range: 40°F (4°C) to 100°F (38°C) Humidity Range: 10% to 95% relative humidity (RH) Audio Alarm: 85dB at 10 feet Test/Silence: Electronically simulates smoke condition, causing the unit to alarm. Press and hold test/silence button. Alarm Reset: Automatic when smoke clears Smoke Sensor: Photoelectric Indicator Lights/Sounds: DC Power: Intermittent Red LED Local Alarm: Audio alarm and rapidly flashing Red LED Listing: Listed to UL217 Standard