Review on Pack Of 10 BNYZWOT MC-31 Wired NC Surface Mount Door Contact Sensor Alarms With Magnetic Reed Switch In White by Davon Man

Thae switches are inexpensive and unfortunately preform as such. While the quantity of 10 (includes screws) is nice for the price, a majority of them do not preform well. Quality varys with some working as intended while others, well under perform. Some magnets are pretty weak and as such must be placed closer than usual (to the point of touching on several). These Switches by themselves do switch on and off as intended but their build quality is questionable. While all 10 pieces worked, you will definately want to use a multimeter to test before installing. With the quality of these varying, thier cheap feel and these being used for windows and doors, I am very apprehensive of their life span. You might be tempted by their low price but I would look at other options that are available here on ebay.