Turn the device around and you can see four narrow, but fairly long ventilation holes on the edges, four holes for ceiling mounting, a battery door and a micro USB connector in case the smoke detector needs servicing. This is available for the battery powered Nest Protect, but, of course, you can also purchase the wired variant, which will have additional AC connector pins on the back side to attach a 230V cable connector. The device itself is not really bigger than the average smoke detector from the market, measuring 1. 63 x 5. 28 inches and the install process follows the same steps: after choosing the rooms in which you’re going to install the Nest Protect at least in every room which has a fuel burning appliance, you need to make sure there is a minimum of 10 feet from any cooking appliance and avoid placing it on a corner you can choose either a wall or the ceiling. Then, you need to take the provided backplate and fix it to the wall/ceiling using the four screws and afterwards, just connect the smoke detector to the backplate using a circular motion if you have the wire powered version, the installing process also includes connecting the device to a power source, but, it’s ideal that this is done by a qualified person, to make sure the installation is made in accordance with the country or state’s regulations.