Retevis MB3 40-Channel AM/FM CB Radio Kit with Antenna, Full Set of Fixed-Mount Kit,ANL Noise Reduction, Emergency Channel 9/19, PA & VOX, Auto-Scan,External Speaker Jack,for Trucker Emergency

Flexible operations: CB radio base station supports AM and FM modes; AM helps you talk with distant truckers; FM enables you to communicate clearly; meeting your various use requirements
Supports PA systems; you can connect an external PA speaker system; NOTES; the external speaker (PA jack) and internal speaker operate independently in single-output mode; only one audio source can be active at a time; when an external speaker is connected; the internal speaker will mute automatically; to use the internal speaker; simply disconnect the external speaker; choose the speaker mode that fits your needs
Clear sound quality; CB car radios have an ANL feature that helps to reduce environmental noise; such as that from car engines; and provides clear call quality; enabling you to communicate clearly in dynamic and moving environments