DZ-1052V02 3-color trackside signal with hooded dual head |O gauge

Dual Headed Signals
Just connect RED wire to power (12-18V AC or DC) and BLACK wire to common to operate.
Upper head is controlled by either the built-in sensor or the YELLOW input wire.
The second or lower head is controlled by the ORANGE input wire. 
Facing the front of the signal, train is detected on LEFT side. 
Sensitivity can be adjusted with the sensitivity adjustment at the front of the base. 
8 secs. after train passes the signal, it changes from RED or stop and after another 8 secs. signal will change to YELLOW or caution.  After 8 more seconds, it will change to GREEN or clear. 
The delay time between aspects can be user set from 1 to 60 sec. 
On the second or lower signal head, the input is ORANGE wire & second output is GREEN wire.