Full battery would be nice.

The smoke detector can be mounted easily, whistles behaved when the stove door open too long and sees something shapely than the usual hardware store copies.
A star deduction is available for the supplied battery is low and let fiepen short regularly at night the alarm ;. Then let the battery yet
Please completely gone, otherwise the buyer is still thought to the (of course, completely wrong) here would ancient warehouse goods sold, in the battery itself is superimposed.

ADDENDUM:
Reduced rating to a point, because it was not the empty battery supplied but which can give a short high-pitched tone of the unit every few hours.
New battery with the same problem. Please do not buy.