Shakespeare Galaxy® Style 5228-4 4' Heavy-duty Extension MastLike the 5228, but 4' length (nominal). Constructed of high-quality Shakespeare white fiberglass, and finished to match Galaxy antennas. This 1 1/2" d"iameter extension mast can be used to increase height of an antenna and thus improve effective range, or to boost placement of an antenna above on-board obstructions.IMPORTANT! If the combined length of your antenna and all extensions is more than 8 feet. you MUST use an upper support bracket