1."Smoke+temperature" dual detection,more accurate alarm,temperature alarm threshold equal 60. 2.When the smoke concentration or indoor temperature reaches the alarm threshold,the alarm be issued immediately. 3.Adopting the optical sensing principle,the smoke concentration can be accurately sensed during the smoldering stage of the fire. 4.When the alarm threshold is reached,an 85dB high-decibel alarm be issued immediately. 5.When the red light flashes quickly,it is to let you know the danger in time to avoid accidents. Wireless type:-loT Working voltage:DC3V (CR123A battery) Low voltage warning:Yes Working temperature:-10-+55 Detector type:Smoke sensing type () Alarm sound pressure: equal 85dB (3 meters directly in front) Battery life:more than 3 years (20 times/day) Colour:White Material:plastic Package Contents: 1 x 1 x English instruction manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.