LiftMaster Photoelectric Smoke Detector (2 Wires) | LIF-LMPD24-2W BDUs Power Requirements: 5 VDC USB

Power Requirements: 5 VDC USB Port Power

or a simple flashlight

RoHS | AWI-MM-6800-GR-MP

Magnetic Autocontrol Strong Full-Strength Spring | MAG-FE21C

SecuraKey USB Mullion Desktop Reader with Virtual COM Port (VCP) | SKY-ET-AUM-VCP

LiftMaster Photoelectric Smoke Detector (2 Wires) | LIF-LMPD24-2W BDUs Power Requirements: 5 VDC USBLiftMaster Photoelectric Smoke Detector (2 Wires) LIF LMPD24 2W The LMPD24 incorporates a state of the art optical sensing chamber and an advanced microprocessor. The microprocessor allows the detector to automatically adjust its sensitivity back to the factory setting when it becomes more sensitive due to contaminants settling in its chamber.