Meet Strips by Sensative: a Z-Wave Plus magnetic door and window sensor with an ultra-thin design that lets you catch intrusion attempts fast. It fits between your door/window and frame. The sensor is weatherproof, so you can use it indoors and outside. The battery life lasts up to 10 years.
Strips is compatible with Fibaro, HomeSeer, SmartThings, Vera, Zipato, and other smart home hubs. It is less than 3mm thin. It alerts you on your smartphone when doors/windows are opened.