These speaker connectors might destroy your amplifier.

These are adapters to connect large gauge speaker wire to a vintage "quick connect" style speaker connector. The fact is, these are absurdly dangerous to your amplifier. Sure, larger gauge speaker wire might improve your sound a bit. If they happen to touch, you won't hear anything at all. The magic smoke with escape, and everyone will be unhappy.

A better option is to attach a short piece of insulated 16 gauge wire to larger gauge wire. The connection should be soldered and covered with heat shrink.