Wireless external siren. For wireless intruder systems that require external audible alarm communications, the SEF8M external siren provides the solution. The strobe light activates as soon as the siren is triggered, helping to identify the property and speed up response time. Siren Output Level: 103dB @ 1m. RF Range: >50m on site (2000m in open field). Radio Type: ALPHA and V2GY (automatic selection). The SEF8M is compatible with all Domonial panels using V2 or ALPHA protocol. Siren Output level Control: Selectable from 0 to 7 plus sweep mode. Cut-off Timers (strobe and sounder): Selectable from 1s to 240s (from point of trigger, the siren knows its sound/flash duration). Battery Type: SEF8M: 8 x 1.5V FR6 AA Lithium batteries, SEF8MDUM2: 4 x 1.5V FR6 AA Lithium batteries. Battery Life 4 years for SEF8M (Profile:4 x 15 minute soundings and strobe per year), 2 years for SEF8MDUM2 (LED working permanently, no sounder). Dimension (h x w x d) 330 x 240 x 73mm. Tamper Rear and Case tamper. Operating Temperature -25°C to +60°C. Approvals EN50131-4 Grade 2. Lens Colour Orange (supplied), Red or Blue (optional).