The system may also include {TAIL ~ an infrared transmitter} for transmitting infrared command signals to a keypad controller having {HEAD ~ an internal infrared receiver} or to an external infrared receiver adjacent one of the drive units 
The system may also include { TAIL ~ an infrared transmitter } for transmitting infrared command signals to a keypad controller having { HEAD ~ an internal infrared receiver } or to an external infrared receiver adjacent one of the drive units
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH