Review on Sky High Car Audio Reducers by Darius Carraway

They do what you need, but be prepared to carefully solder the ends before inserting into the adapter. The allen wrench is too small in diameter and length to grab enough wire without pre-soldering. I use them to match the 10ga speaker output of an ORION HCCA 8000.1 to four 8ga cables. The four 8ga wires are oversized and fit great without the need to cut them and remove the copper. The 4ga end of this adapter fits perfectly into the amp's 10ga output. Overall I'm happy with this item, plus you still have to solder all your connections and ends.