[TowerTalk] Split bolt connectors

[n0tt1 at juno.com]

Gents, could some please decipher this
split-bolt connector size?

"ABI 16-4 SOL S-4" 

I'm guessing it's an ABI brand, other than
that I'm not sure what the "running" size is
and then the wire "tap" size.  I've looked
on the web with mixed results.

Thanks,
Charlie, N0TT