Honeywell 958-2 Overhead Door Adjustable Magnetic Contact, SPDT Switch (Form C), Adjustable Magnet with L Bracket, 24" (61cm) Armored Cable is Standard, 2-3/8" (60 mm) Minimum Standard Gap

Having used these contacts many times, they are just what I expected.

High quality devices.Worked for my application perfectly.I used these on a electric gate to replace failed magnetic switches.Could not have retrofitted easier !!!!!!!

I ordered two of these because I wanted to have feedback for when the garage door was closed, when it was open, and when it was in motion or partially open. I pop riveted the magnet bracket to the top of the garage door, mounted one reed switch at the top of the jamb for the closed position sensor, and the other I mounted near the opener for the open position sensor. The reed switches are single pole double throw, so they have three leads, a common, a normally open, and normally closed lead, so you can choose which you need or use both. They reed pulls down when the magnet is about 2" away. The conduit portion of the cable is 24" long, the body of the reed switch is 4-3/8" long, 1-3/4" wide, and about 1/2" tall. They seem quite sturdy, epoxy sealed, and have been trouble free for me so far.