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.