RDM HD Aluminium Mast Extension Heavy Duty 30cm goodolboards.com Shakespeare 5228 1 Galaxy 12" Heavy Duty Antenna Extension Mast **New 54" White & Silver 5228 4 Heavy Duty Extension Mast Christmas Central 54" White & Silver 5228 4 Heavy Duty Extension Mast Christmas Central. Shakespeare Galaxy Style 5228 4 4' Heavy duty Extension Mast Like 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 Stainless steel upper and lower ferrules with standard 1" 14 thread Suggested mount: Shakespeare Style 409 R or 410 R Mounting Kit One section, actual length 44" Shakespeare Limited Warranty: 5 Years