4.5-inch speaker from Astatic. Includes a noise-canceling feature for reducing unwanted noise as well as talk back gain control so you can listen to yourself while you re talking. Also features a PA input 8-ohm impedance a 10-foot power cord with 3.5mm plug mounting bracket and hardware. The talkback function only works with specific CB radios including Cobra 25 29 and Uniden 68 78.