If you are going to use ring terminals, you should open end crimp style like these and solder them when using 4 gauge to 0 gauge wire. Its a little more work but in my opinion its the right way to go. It does take more time than just crimping them only or using set screw style terminals but if done right the end result is the same if not better so why pay WAY more for 1 set of terminals when you can get 10 for this cheap. It's a no brainer to me, but thats just me.