Sirio mag mount for amateur or CB aerials requiring the so 239 fitting. Very high quality, Sirio is well known for its aerials and accessories. 145 mm or nearly 6 inches in diameter (5 7/8''), which makes it perfectly adequate for CB aerials up to and including the Sirio megawatt 4000 and similar sized amateur aerials. Supplied new and unused with a 12' RG58 coaxial lead fitted with a PL259 plug and weather-cap.