Engineer-friendly:

• a self-supporting lid, built-in spirit-level and revolving fixing holes for ease of installation including on uneven surfaces.
  

High-power comfort LEDs and LED strobes:

• Provides reassurance for the user.
  

Common enclosure for entire range:

• impact-resistant polycarbonate construction.
  

Features:

• Selectable between Self Contained Bell (SCB) or Self Actuated Bell (SAB) modes:

- In SCB mode the sounder, in alarm condition, draws

 its power from its integral internal battery

- In SAB mode the sounder is driven from the control panel

- Low-volume maintenance mode

- Self-supporting lid

- Built-in spirit level

• Sound output 100 dB at 1 meter
  
• Low current consumption (35mA and 225mA in-alarm current)
  
• Lid and rear tamper detection
  
• Selectable cut-off timer
  
• Choice of siren tones
  
• Compliance: EN50131-4 Grade: Grade 2
  

(SDR-WEXT-G2 and SDR-REXT-G2), or Grade 3

(SDR-WEXT-G3),PD6662:2010, EN50131-4:2009