AAA to AA 1.5V Battery Adaptor

There are 3 choices: - Adapter with 5mm M3 screw

- Adapter with 4 mm M3 screw

- Adapter with 3mm M3 screw

It appears to me that 5mm is the most popular, then 3mm, and 4mm. However, with the 4mm screw, you get the best size.

The adapter with the 5mm screw is slightly large, while the 3mm adapter is a bit small.

Or alternatively, you can simply grind down your 5mm screws to 4mm~

The STEP design files are available. Feel free to remix!