This is NOT the original Diamond X50 antenna, rather a replica of it. Nevertheless, the appearance of this X50 is indistinguishable from the Diamond X50. Specifications are also identical, according to both manufacturers.
The antenna was installed on about 4m height. It shows SWR~1.2 at VHF and SWR~1.3-1.4 at UHF from one end of the bands to the other. It has an N-connector at its base.