Hyperlink antennas

[kd5dga]

I recieved a catalog a few days ago from hyperlink technologies.
They advertise 900 mhz antennas.
I wonder how usefull these antennas would be for 900 mhz trunk radio systems?

http://www.hyperlinktech.com/category.aspx?id=71

 

[fineshot1]

The omni's & yagi's look like they have about average specs and the prices are not too bad either. Not sure if the other types would be of any use. I have never seen anyone use any of those types for a trunked radio system.