Antenna ExtendersConstructed of high-quality reinforced fiberglass and finished to match Digital Antennas award-winning antennas, our antenna extenders are used to increase the height of an antenna to improve effective range or to place an antenna above on-board obstructions that may interfere with proper radiation. All extenders mount standard 114 threaded mounts. Use a center brace when the combined length of your antenna and all extensions is more than 8'All Antenna Extenders Feature:Heavy duty fiberglass Stainless steel ferrules 114 threaded top and base High gloss urethane finish 528-EWDimensions: 4' - 1 O.D.This product may not be returned to the original point of purchase. Please contact the manufacturer directly with any issues or concerns.