I bought this antenna from an Amazon vendor after comparing reviews of similar antennas. My experience is only one data point, but this antenna functioned for only a bit more than a month before failing. It was mounted on the cowl of my Toyota Landcruiser, so not in a place of extra ordinary heat, vibration or other conditions that I would have thought might cause failure in a product purportedly intended for use on a vehicle or vessel.For the short time it did work, it was not noticeably better than a less expensive Garmin auxiliary antenna I owned previously. The Garmin died after about 18 months, and was mounted in a similar spot on my Range Rover Classic.For the record, this vendor warrantied the antenna and offered an immediate replacement.