The Metz SCA 3045 Converter & Extension Cord is the required extension cord that maintains full compatibility between the 45CL-4 Digital and advanced digital cameras. The cord connects to the handle-mount 45CL-4 Digital flash, and other end to the appropriate module, which then connects to the cameras hot shoe.
Also backwards compatible with older SCA systems, albeit with some loss of function.
Reviews Metz SCA 3045 Converter & Extension Cord - Adapts 3000/3002 Series Modules to the 45CL-4 Digital