Texas Ranger SRA-166FB. Frequency Counter built inside an
exxternal speaker. For radios that have a 6 pin Freq Counter
jack in the back of the radio.
Cobra's HighGear external speaker S300 Noise Canceling Filter for clear receive
audio, 15 Watt power handling capability, 4-inch speaker
with 5.5 oz. magnet, shock resistant construction, Metal
mesh grille. Also has a 3.5mm (1/8") headphone jack for easy
earphone plug-in location when you want to hear but the
passenger does not.