Functions as a central "distribution" hub for EOS TTL off-camera operation, and will accept up to four Connecting Cords (one to camera, three to flashes). To be used with TTL Hot Shoe Adapter 3 ( # 2438A001 ) or Off-Camera Shoe Adapter OA-2 ( # 2447A001 ) and EOS Connecting Cord 60 ( # 2387A001 ) or 300 ( # 2388A001 ) for off-camera TTL use.

Note: Provides standard TTL or manual flash control, but not TTL or TTL II. Not compatible with EOS digital SLR cameras.