State of the art smoke alarm designed to provide early warning of a fire. It features a fully insect screened dual ionization smoke sensing chamber, an 85dB horn, a supervised 9V alkaline battery power supply, a full function test switch, a silence feature to silence unwanted nuisance alarms, a red LED light that indicates DC power or alarm. It also features a tamper resistant locking pin that locks alarm cover to prevent removal of battery. Perfect for RV use.