Window and Door Sensors: $39/each. Protect America offers several different types of sensors. They have the door and window sensors which detect whenever the door or window is opened. The Protect America door and window sensors are wireless microsensors which means they do not have to be plugged into your wall and are hidden out of the way.
Shop Our Collection of Doorbells for Business, Wireless Doorbells, Entry Alert Chimes & Wired Doorbells Warehouse Doorbells for Loud Areas. Great for Warehouses, Stores & Business. Strobe Lights, & More Our warehouse doorbell kits features optional strobe lights, sirens, bells, & buzzers making... The very simplest alarm would have a switch on the driver's door, and it would be wired so that if someone opened the door the siren would start wailing. You could implement this car alarm with a switch, a couple of pieces of wire and a siren. Most modern car alarm systems are much more sophisticated than this. They consist of: