Your missing out if you haven't replaced your 20-30 year old speaker with our updated communications speaker made by the same manufacturer Collins contracted with. Delivers the desired warm audio from your tube type equipment. Many hams order extra after trying out this new design. Slips right into same mounting as original speaker in B3, B4 or B5. 5" x 7". Low, 4 ohm impedance. Join the club! Also fits Drake MS-4 Speaker cabinet. A perfect replacement!