The Gentex 7100F is an audible Photoelectric type detector that allows use of other Gentex hardwired equipment (S120 Remote Strobe / 710CS series & 7100F smoke detectors) to create an individual system that incorporates sound and strobe alarms. The 7100F is ideal for rooms where only an audible detector is required. The 7100F must be hardwired and requires an electrician to hook it up. The unit delivers outstanding performance and can be used in residential, commercial and industrial applications. 1-year manufacturer warranty.