Intro: Parameter Alarm.
Perimeter alarm for airsoft
Step 1: Materials
To make this all I used was a magnetic alarm that I found at a dollar tree for a buck and I used some clothes pins I had laying around the house. Then I put it all together with a hot glue gun. Sorry for not having images for the materials.
Step 2: Glue.
I tore apart the clothes pins and glued them to the alarm.
Step 3: Test Magnet Position.
I glued a full clothes pin on top of the alarm. But before you glue it make sure the alarm will go off when the magnet is pulled from the clothes pin.
Step 4: Paint and String.
After the glue dried I painted the alarm. For the line I used regular fishing line. Stick the alarm in the ground with the clothes pins and tie the line to the magnet. Hide it and tie the line from the magnet to something else like a tree and whenever the line is pulled it pulls the magnet and the alarm goes off.