You got here most likely due to your hallway smoke detector going                                                                                                                                       
beep. Its dead, or about to be. It's 10  or more years old, no longer                                                                                                                                   
made. The warranty has expired. Replace them ALL with something.                                                                                                                                        
This is a replacement for the DICON unit, and from what I'm told they                                                                                                                                   
are a direct snap in unit, look at the pictures. You may want to get                                                                                                                                    
SA379UL's as an upgrade. Same model, but with a 9V battery backup,                                                                                                                                      
smoke works when power is out. This is the U.S. version, for Canadian                                                                                                                                   
version see SA360, SA379. A good shipping box is 6 pieces. takes about                                                                                                                                  
a week, tracking number, insurance. Thes units have a 10 year warranty                                                                                                                                  
FEB 2008 THIS ITEM WAS DISCONTINUED SUB WITH SA379UL                                                                                                                                                    

                                                                                                                                                                                                   
        1-6       7+                                                                                                                                                                                    
$C     20.62   19.82                                                                                                                                                                                    
$US    20.00   19.23                                                                                                                                                                                    
EURO   13.40   12.88