Source For Sensors?

["Hank Murphy" <hmurphy@xxxxxxxxxxxxxx>]

We have a home alarm system, installed about 15 years ago, with an Acron
control.  About two weeks ago someone was working on the roof, and evidently
the vibration caused the door magnetic sensor to fall out.  We did not
notice it, but now the door zone is always lit.

The sensor looks to be about 1/4" in diameter.  The magnet is still in the
door itself.  It's hard-wired, not wireless, if that is not obvious.  Can
someone recommend me a source for online parts ordering?  (I will just order
two, one each normally open and normally closed, since the shipping is
usually more than the items themselves.)

I can't locate the paperwork for the orginal installer, so that's out for
the moment.  I plan on replacing it myself, as the wire location is
reasonably accessible in the attic.

Thanks in advance for any advice,

Hank Murphy