Bộ chuyển đổi 2xCR2 sang 2xCR123

Dual adapter ensures minimum resistance. 
You will also need a piece of aluminum foil as conductive spacer inside the tube.

If it's too tight or too loose - feel free to scale the model by few % on X/Y axis. Batteries should not fall out, but should be removable with small, reasonable force.

Remember that you can only use 3-3.2V batteries (i.e. LiFePo4). 3.6V (4.2V) Li-Ion batteries might burn your camera.