This BRK(R) smoke detector utilizes photoelectric smoke sensing to procure reliable protection. The unit comports the patented technology OptiPath(R) designed to provide an unobstructed 360° access to the smoke detector as well as a 10-year lithium battery backup. The smoke alarm features a stroboscope with 177 synchronized LED lights to provide effective visual warning intended to waken hearing impaired residents. When multiple units are installed, strobes flash in unison. This product is backed by a 10-year limited warranty.