LF-SD-41 Conventional Photoelectric Smoke Alarm with BatteryThis standalone smoke alarm utilizes advanced photoelectric technology to provide reliable and early detection of smoke, particularly from slow, smoldering fires. Designed for residential and commercial spaces, it features a loud 85dB horn and a simple test silence button, ensuring occupants are alerted promptly to potential fire threats. Key Specifications: Model: LF SD 41 Detection Method: Photoelectric Sensor Power Source: 9V DC Battery (Included)