Heavy Duty Wired Alarm Garage Door Magnetic Contacts Switch Sensor NC with Adjustable Bracket

Good product. Just as described.

Bought these, as opposed to cheaper, smaller, plastic ones, as they had good reviews, appeared to be fairly heavy-duty, and yet were basic switches I needed for my dry-contact firmware for a home automation device (RATGDO for anyone counting).They are significantly larger than the small plastic ones, but since I've had them installed (maybe ~ a year now) they are rock-solid and just plain work. Love the wrapped metal cabling at the end, which makes me feel they are more durable (and they probably are), and I mounted them with 3M double-sided tape, to the aluminum rail and framing of my garage door.

I have six of these industrial grade garage door sensors in use and have had great luck with the reliability. You don’t have to mount them on the floor to work, they also work great at the top of the door.

I used this product to replace an older set of alarmed garage door magnetic contacts that were of much lesser quality and had failed...I was concerned about the strength of any replacements until I found this product online. I must say, I am very pleased with its quality, ease of installation and performance. I highly recommend it. It can be purchased in a NC (normally closed by the magnet) or NO (normally open by the magnet) depending on customer need.

Lo uso con un Shelly 1 para controlar un portón y funciona super bien, simpre me indica si el portón está abierto y cerrado.

I love this sensor for my WI-FI garage gate opener, has a random gap distance variation every time I open and close the sliding gate. Now know when the gate is open or close with a warning indicator with error proof of false alarms.

As a combination, switch and magnet this is a NC switch. The switch alone ic NO- Normally Open held closed by the magnet.. IF you want wetting voltage to power a horn when a door is opened, this will not work. This will have the horn sounding all the while the door is closed, then shut off when the door open. You may want that, but be sure. I believed they described it somewhat correct, but more correct it should be described as a NC switch, held open with magnet. The contact alone should be a NC Normally Closed contact. That way with the door closed and in proximity of the magnet, the contact is opened and no voltage passes, but as the door opens and the magnet moves away, the contact closes and powers some device, such as a horn letting it be known a door is open device.

I recently purchased the Heavy Duty Wired Alarm Garage Door Magnetic Contacts Switch Sensor NC and I have to say that I am overall satisfied with its quality and durability. The adjustable bracket makes it easy to install and the NC function provides peace of mind knowing that if the door opens unexpectedly, the alarm will sound.However, I was disappointed to discover that the product did not come with any concrete or masonry hardware to attach it to a concrete floor. This added an extra expense and inconvenience as I had to purchase additional hardware separately. Additionally, the wire was too short to reach my desired location, but this can be remedied with a longer wire.Overall, the product is well made and I appreciate its durability. I would recommend it to others, but with the caveat that it does come with some limitations