^^^
My speaker
wire 
, 14 ga., was a tight fit for the ends....and they're supposed to fit up to 12 ga. wire. The little set screws were about the size of eyeglass bow screws.
The old connections were the 'twist the wire' type and hope it gets clamped down.
The Sony amp has three diff types of connectors on the back and these things worked for all of them.
It looks like those Polk's have good shape foam.
.