SpeedDa 6 Sets Magnetic Reed Switch Normally Open Closed NC NO Door Alarm Window Security/Magnetic Door Switch/Magnetic Contact Switch/Reed Switch for GPS,Alarm or Other Device,DC 5V 12V 24V Light

Configurable for normally open or closed. Quality. Great value. Eliminates guesswork. Perfect setup for me for low voltage closet lighting.

I like that they came in a clear plastic box that made it easy to store unused ones. I used them to trigger LED cabinet lighting and they worked perfectly. Having the ability to wire NO or NC is a great benefit that not all connectors like this offer. I will order these again for my next project.

There are several reviews claiming these are labeled wrong, but these are labeled correctly for a magnetic switch! The 'Normal' position for a magnetic switch is with the magnet PRESENT, so when the magnet is present, the NC contacts will be closed, and the NO contacts will be open.Most 2 wire magnet switches are NC, and used with alarms, so that when a door or window is opened and the magnet moves away, the circuit opens, and triggers the alarm. This makes sense because it means if someone cuts the wires, the alarm will trigger.If you want to use these to turn on a low voltage light when the magnet is not present, you will use the NO contacts.

I tried several different reed switches before I came to this one. I wanted to add LED lights to some closets and cupboards to make it easier to find things (and hopefully impress my wife). The problem is that while online you will read that "Normally closed (N.C.)" means that the circuit is closed (electricity is flowing) when the magnet is NOT present, in fact every reed switch I bought was backwards. Some did not work at all, but those that did took "normally closed" to mean that electricity flows when the magnet IS present.That is why I ultimately chose these reed switches; since they cover both operations, I figured they couldn't go wrong. In fact, "normally closed" and "normally open" are still backwards on this reed switch, but I just connect to the "normally open" terminal and it works how I want. When I open the door, electricity flows from the four AA batteries into the LED strip. I bought the battery pack and LED strip together, and simply cut a wire and inserted the reed switch into the circuit.You can connect these reed switches either by adhesive strips or by screws. There isn't much difference either way. They are also durable and easy to use (with screw terminals). They have arrows, too, which make it clear where the actual reed switch is and thus how you should align the magnet (which is included).They aren't the smallest reed switches, but they are not huge either. They are mostly plastic. If you need smaller, you could conceivably buy it, open it up, and use the circuitry without the plastic case.Best of all, my wife was impressed to find her dark cupboards illuminated at last.

Worked fine, but the screws included are low quality and can strip easily if not careful. It needs a pilot hole to screw in.

Perfect for my small projects. I love that I can choose NO or NC as I see fit. Plus, then I don't have to figure out which a manufacture means by 'normally'. (Is normal with them together? Is normal with them apart?). If you pick the wrong one, just change terminals.

I'm not sure if I should be amused or alarmed (no pun intended). These switches are mis-marked in that the NO and NC contacts are reversed. The center connection is actually the NO terminal and the NC connection is the terminal at the end opposite the COM terminal. Maybe a problem in translation? The connection between the COM and NO terminal should be made only when the magnet is close enough to trip the internal switch contacts. When no magnet is present the NC and COM terminals should show essentially zero ohms resistance. I gave the switches a 3 star rating because the function and quality seem to be OK for the cost. Anyone using them should catch the marking error.

I tested all of the order and they all worked fine in both modes. Now, how long will they really last? All of my previous mag. switches, a different maker, ended up failing at some point.