Here is a 1-Watt amplified loudspeaker for low amateur radio or for operation with a mobile amateur radio requiring more volume. The MFJ-382 speaker is 3 inches. Adjustable from barely audible to loud, this speaker is sturdy and compact. All metal with rubber feet measures 3 1/2 x 1 3/4 x 4 1/2 inches. On / off button, uses a 9 volt battery (not included) or 110 VAC with the optional MFJ-1312D. Speaker cable included.