The cable. There should be fine (But can be seen, just that it's lightly colored) printing along the cable. That and the connector has a tri-wing screws.
Thanks for this, I will use it for reference later on. Luckily my wiimote nunchuck combo is ORIGINAL!
Btw, no reference to check a fake motion + weyh? (If there's any)
Wii Remote + Nunchuk ( FAKE ? ), Pictures Side by Side