User's Manual
14 
VOLUME CONTROL: The switch toward the middle of the board, numbered “2” controls the 
volume level of the horn. To reduce the volume level, press the rocker switch toward the “OFF” 
or “OPEN” position. To restore full volume level, press the switch toward the “ON” position. 
Horn printed circuit board
Switch
number “1”
Switch 
number “2”
7.0 Product Selection Guide: 
  7.1 F21 Models 
Complete Systems 
Model 
Typical Applications 
Number of 
Motion Buttons 
& Steps 
Control 
Voltage 
Number of 
Transmitters 
F21-2S 
Hoist, winch, lifts, doors, 
conveyors etc… 
2 button, 1 step 
110-220VAC 
1 
F21-2S-DC 
Truck Equipment, winches, 
hoists, etc… 
2 button, 1 step 
12-24 V 
AC/DC 
1 
F21-2S-2TX 
Hoist, winch, lifts, doors, 
conveyors etc… 
2 button, 1 step 
110-220VAC 
2 
F21-2S-DC-2TX 
Truck Equipment, winches, 
hoists, etc… 
2 button, 1 step 
12-24 V 
AC/DC 
2 
F21-4S 
Monorails, dual hoists, etc…  
4 button, 1 step 
110-220VAC 
1 
F21-4S-DC 
Truck Equipment, 
monorails, dual hoists, etc… 
4 button, 1 step 
12-24 V 
AC/DC 
1 
F21-4S-2TX 
Monorails, dual hoists, etc… 
4 button, 1 step 
110-220VAC 
2 
F21-4S-DC-2TX 
Truck Equipment, 
monorails, dual hoists, etc… 
4 button, 1 step 
12-24 V 
AC/DC 
2 
F21-2D 
Hoist, lifts, etc… 
2 button, 2 step 
110-220VAC 
1 
F21-2D-DC 
Truck Equipment, hoists, 
lifts, etc… 
2 button, 2 step 
12-24 V 
AC/DC 
1 
F21-2D-2TX 
Hoist, lifts, etc… 
2 button, 2 step 
110-220VAC 
2 
F21-2D-DC-2TX 
Truck Equipment, hoists, 
lifts, etc… 
2 button, 2 step 
12-24 V 
AC/DC 
2 
F21-4D 
Monorails, dual hoists, etc… 
4 button, 2 step 
110-220VAC 
1 
F21-4D-DC 
Truck Equipment, 
monorails, dual hoists, etc… 
4 button, 2 step 
12-24 V 
AC/DC 
1 
F21-4D-2TX 
Monorails, dual hoists, etc… 
4 button, 2 step 
110-220VAC 
2 
F21-4D-DC-2TX 
Truck Equipment, 
monorails, dual hoists, etc… 
4 button, 2 step 
12-24 V 
AC/DC 
2 










