The most secure installations would use one of each type connected in series.

Most installations used it to develop simple systems that required a low level of sophistication, and had a small budget.

Many European installations are now using this setup due to the ease of installation.

Several commercial installations use this type of battery for load leveling.

Older installations in some other countries, including France and Greece also use this base.

Here is one installation, using motion sensors to automatically open the door:

The most common is remote installation, using a backdoor created by a computer virus or trojan.

Most installations use the optional directional antenna on the bottom of the aircraft.

The installation, for which the previous one was a useful trial balloon, again uses "Snake" as a connector in the middle.

Loading coils can still be found in some telephone landlines today but new installations would use more modern technology.