In addition to working with the Nikon autofocus cameras, the Metz SCA 3402 adapter also brings wireless TTL auxiliary flash capacity to other makes of cameras when combined with Nikon's #3073 SU-4 wireless slave flash controller.  

For example, if you had a camera with TTL flash capacity but did not have a cord to connect the system to an auxiliary flash and wished to have TTL with a second off-camera flash unit, you'd be out of luck. But not so with a Metz 32-MZ2, 40-MZ, 44-MZ or 54-MZ series flash; simply attach the SCA 3402 foot to a Nikon SU-4 slave controller and this combination will effectively mimic the power from the main flash!