FC-311 is Canon EOS series camera and flash off-camera cable. It connects the camera and flash to precede off-camera sync flash. Its support all functions of EOS series and flash TTL function.
FC-312 is Nikon camera and flash light off-camera cable. Its connect Nikon camera and flash light to precede off-camera sync flash. Its support AF assists focus function, which same as top on camera. Its also support high speed sync shooting and creative lighting system, included I-TTL, BL, FP and shutter speed up to 1/8000S.
This is an 11" 2-Pin LEMO to P-Tap Cable, from Teradek, for powering the 2-pin LEMO version Cube, Bolt, Bond, and Link from a P-Tap power source.