This adapter set allows the use of SAE connectors to JIS (Pencil Post) terminals.
Some years ago, I replaced the 12v battery in my Prius, and I converted the car's battery cables to full sized for the full sized battery I put in as a replacement. Fast forward 6 more years, and it's time to once again replace the battery on my Prius - but I forgot that I made the conversion... I got a great battery, for a great deal, but the posts were the tiny "pencil posts", and now I can't find "Prius" style battery clamps... I found these adapters and they are PERFECT!!! fit exactly as I needed them to and allowed me to clamp down on that new battery with normal sized clamps.
These adapters are a godsend for things that don't fit.