Speco's  6" aluminum PA horn is weatherproof. It offers a frequency response of 250 to 15,000 Hz with a 10 watt RMS/15 watt maximum power rating. It features a 105 dB sensitivity and an 8 ohm impedance. Technical Specifications Dimensions 6" (Dia) x 6" (L) Frequency Response 250-15,000 Hz Impedance 8 Ohm Material Aluminum Max Power 15 Watts Mounting Bracket Included RMS Power 10 Watts Sensitivity (1W/1M) 105 dB

If You're Going to use this for Your CB Radio, You'll Need This  SPW10P