True to scale, each bar has 8 LED?ås in groups of 2, plus a dome. Finally, you can easily add authenticity to police and emergency vehicles in your diorama. All units are fully assembled and they come\r\nwith instructions for mounting in a police car, fire truck or emergency vehicle. They operate on 9VDC, batteries are not included, and battery snaps are included. There are two units of the same color\r\nin each package. In addition we have included 2 latchingpush button switches.\r\n\r\nSEE VIDEO:\r\n\r\n="http://www.youtube.com/v/POZxVFPlS7g?fs=1&hl=en_US">