Battery Operated Smoke Alarms, Smoke, Ionization, 5.6 in Diam ORS NASCO especially for heavier gloves Straight thumb especially for heavier gloves Straight thumb increases comfort in closed fisted work Slip on cuff allows for easy on and off Heavy weight is excellent for cold applications rubber or metal horn and battery function Low battery indicator—Smoke alarm will chirp in the event of a low battery Red LED—Flashes every 30 40 seconds to indicate that the smoke alarm is receiving power Dust cover Battery operated—Easy installation and continuous protection even during power outages Test button—Tests unit's electronic circuitry