How to Make Your Own Camping Trip Alarm – Outdoor Command
DIY Trip Alarms | Tripwire Alarm Store ~ Perimeter Defense Systems
Shotshell primer perimeter alarm system with Kevlar tripwire and my added touch, a modified junction box for weather housing and holes to feed vines or camouflage netting through. : r/Survival
Sentry Alarm Mines, Trip Wire Alarm - Made in the USA