The receiver is normally powered from the operator or machine electrical supply. Standard power requirement is 24V AC, but can also be modified to suit 120V AC (at extra cost and must be specified]. The receiver cornes with a built-n external antenna. Areas where signal interference is high, an extended cable can be supplied to lengthen the antenna to the exterior of the building or gate/barrier control cabinet. This eliminates interference and maintains the 100 meters (325 ft) perimeter. Note: Also available for NEMA 4 & 12 application.