Butt splice connector to join 10 gauge to 12 gauge wire?

OP here: Someone asked about voltage -- this is 12 volt. And again, thanks for all of the advice.

I think I will have to buy a crimper -- not going to use pliers. I understand that solder is the gold standard, but only if the soldering is done by someone who is competent. I'm not -- I so seldom need to solder that I have not developed the skill.

The project I am working on will involve a total of four connections, and that will probably be my sum total for this year.