The SC-29 is an off-camera flash cord that provides full TTL control for Nikon Speedlites when used with Nikon SLR cameras which have the TTL hot flash shoe. 3' long when coiled, it expands to 9', and permits easy use of flash when the camera is mounted upon a bracket.
In addition, the SC-29's AF Illuminator will also provide AF assistance to the camera in low-light conditions. This cord fully supports all advanced flash functions when used with the SB-800 or SB-900 with an applicable camera.
Some other improved features are: Posi-Lock (an improved locking switch) at both ends, and the cord on the camera shoe that now connects parallel to the camera.