OBSERVER™ LIGHTWEIGHT REMOTE SPEAKER MICROPHONE. Smaller size more convenient for users who want the features of a speaker mic but in a smaller size. Speaker output of a much bigger mic and also has a 3.5mm jack for optional earphone.
Very popular Vertex Standard radios with 1-pin and 2 retaining screws including: VX-130 series, VX-160, VX-180, VX-210, VX-230, VX-231, VX-350, VX-351, VX-354, VX-400, VX-410, VX-414, VX-417, VX-420, VX-424, VX-427, VX-427A, VX-450, VX-451, VX-454, VX-459, EVX-530 (eVerge Digital), EVX-531, EVX-534, EVX-539.