To boost AM and FM radio reception for heavy duty vehicles then the CR66-HD-TPM is your ideal solution, it comes standard with a 5/16"-26 Brass thread.
AM radio 530-1600kHz and FM radio 87.5-108MHz
H Plane: 360° omnidirectional receive
Black heatshrunk heavy-duty fibreglass whip and chrome ferrule
5/16"-26 TPI female thread
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