Stand Alone Smoke Alarm is Designed to Provide Early Warning of Presence of Fire by Emitting Sound Signal. Its 85db Sound Alarm is Powerful Enough to Wake You Up in Case of Emergency. It Ensures Youll Gain Precious Minutes to Escape Before Fires Propagation. It Detects Smoke From Wood, Cotton, Plastic & Hydrocarbon Based Fires. However, Device is Effective Only When Located, Installed & Maintained in Compliance with Instructions Described in Manual. Device Does Not Detect Gas, Heat or Flames.