Bidirectional wireless (868Mhz) sounder. Includes 1 piezoelectric. Low consumption stroboscope. Polycarbonate housing. Internal electronics with protective cover. Arming / disarming indication with LEDs. Alarm delay function during installation. Wall and cover tamper. White cover not included. Sound level: 98 dB at 1 meter. Dimensions: 290 x 285 x 50 mm. Power supply: Battery BATT-ES1 included (Lithium 3V / 5A). Grade 2.