Need info. on Meadowlark Heron i speakers

I am looking for some info. on the meadowlark speakers called the heron i, what is the impedance of this speaker, what type of spikes and thread size fit these speakers?
You can most likely find info at buried somewhere in their site while it is still up.

I am not certain but the newer line was using 1/4 20 on the threads...
Check this link here:

I also have a pair of them which I'll be selling shortly. They are terrific speakers IMO.