Add $175.00 for FREE shipping
Shop All!
Sensor Type
Door / Window
Contact Closure / Relay
Outdoor Rated
Normal State
Normally Open
Ease of Installation
Beginner (Installs < 10 minutes)
Other Ways to Shop
In Stock
On Sale
Order the Smarthome Catalog

Boost your Home Security System with Sensors that Send an Alert When a Door or Window is Closed
SECO-LARM SM-300Q/WH Surface Mount Magnetic Contact Switch, Normally Open (10-Pack)
Seco-Larm Enforcer SM-300Q/WH Surface Mount Magnetic Contact Switch, Normally Open (10-Pack)
Click for larger image and other views
X-10 Wiring Diagram Window Installation Compact Size
Seco-Larm Enforcer SM-300Q/WH Surface Mount Magnetic Contact Switch, Normally Open (10-Pack)
Item# 7040-10
Price: Normally $59.90 
Hot Deal $25.99
Free shipping on orders over $175 - See Details


  • Works with nearly all standard, hardwired alarm systems
  • Designed for use on Normally Open (NO) applications
  • Use on doors, windows, and sliding doors
  • 3/4 inch Operation gap
  • 10-pack saves you money over buying individual units

Essential Info

For added protection around your home, add a pair of Surface Mount Magnetic Contact Switches to almost any security system. There are 10 pairs of switches included in this kit allowing you to monitor multiple areas around your home. These switches are ideal for any normally open location and will send an alert signal to your security system when it is no longer in a normally open state. Simply mount the magnetic sensors on a door or window so that the two are in contact with each other when the door or window is closed. Slotted mounting holes make it easy to adjust the distance between the magnet and the sensor, with a maximum operational gap of 3/4 inch. Measuring 2.48 inch long and half an inch high, they can be attached with wood or sheet metal screws, sold separately.

This Normally Open Surface Mount Magnetic Contact Switch is also available individually.

A Normally Closed Surface Mount Magnetic Contact Switch is also available.


What's Included

  • 10x - Surface Mount Magnetic Contact Switch, Normally Open (10-Pack)
  • 1x - Owner's Manual
  • More Info

    Other Features
    The switch is waterproof and mounted in a high-impact plastic case. The rhodium plated contacts handle up to 100mA at 100 volts DC and are rated for 50 million openings and closings. It can reliably operate in temperatures between -15°F and 160°F. The sensor's maximum operational gap is 3/4 inch.



    Manufacturer Product No.:SM-300Q/WH
    Weight:0.05 lbs
    Dimensions:2.48" x 0.5"
    Compatibility:Closed circuit systems


    X-10 Wiring Diagram  Window Installation  Compact Size   
    X-10 Wiring Diagram  Window Installation  Compact Size   


    9 Ratings
    5 star: 56%  (5)
    4 star: 11%  (1)
    3 star: 22%  (2)
    2 star: 0%  (0)
    1 star: 11%  (1)
    Average Customer Rating
    (9 customer ratings)
    Share your thoughts with other customers
    KENDALL -- chagrin falls, OH   5/11/2013
    Product is exactly as described. Works great for my project. Thanks for the great description. I purchased from Smarthome because their description was clearer than others and I could be sure of getting the correct type of switch.
    MATTHEW -- danvers, MA   4/7/2012
    So far I have used 4 of the 10 switches in the pack, and 2 have been defective and I've had to replace them already in under a week.
    MERVIN -- middletown, PA   3/30/2012
    great service pleasure doing bussiness
    HENRI -- murphy, SC   4/3/2011
    Prompt shipping, correct product, and a successful project at my end.... Thanka
    KEVIN -- goshen, IN   11/12/2010
    Very friendly sales person, fast service and quality product. Dana L.
    DENNIS -- saginaw, MI   11/1/2009
    Okay price, okay quality. Does the job well.

    Related Items

    Customers Also Bought

    Sign-up for Exclusive Email offers 
    How to Order Track Your Package Shipping Returns Contact Us Customer Service Retail Store
    Getting Started Learning Center FAQ Dealers Customer Testimonials Affiliate Program
    About Us INSTEON Press Awards Employment Guarantees Security & Privacy
    Free Catalog Email Newsletter Forum RSS Site Map
    Have questions? Call us at 800-762-7846 (Mon-Fri 5am-7pm and Sat 6am-3pm PT) or send us a message
    Place your order by 3pm PT for same day shipping
    Copyright 1995-2014 SMARTHOME™
    Verisign Secure Site PayPal Acceptance Mark