This Custom made Aluminum Milled, Antenna Capacity Top Hat Clamp Assembly, consists of two Aluminum plates that measure
4 3/8 inch diameter. Each plate is milled out to accept 5/16 inch radials and is about 1/4 inch thick.
With more low band activity, it is very useful to add this clamp assembly and capacitance elements to be able to shorten your low band vertical antenna.
If you reverse one of the plates, you can use 3/16 inch elements.
The center hole is 1/4 inch.
I also sell 1/4 inch couplers with two set screws that can be used above and below the disc assembly to keep it in place.
These were made for a specific project which was cancelled and I have only a limited supply.
The discs can be modified to suit your needs. You can drill holes through, to hold the clamp together tightly, to secure the elements.