I had these made for me to make some 23cm stacked dipole arrays however tuning was slightly off. Using the mounting pole as a reflector you can lower the vswr on these right down to about 750mhz, as they stand there are tuned approx 1400mhz with no mounting pole or reflector nearby.
These are sold as seen and surplus stock, all working but no longer need for my requirements. 
You could easily make a stacked 23cm array with these.  Giveaway price of £1.50 to clear