The off-camera shoe cord is an exclusive accessory for EOS series cameras which allows an external flash to be used away from the camera. The flash can be located as far as 0.6m/2ft. away from the camera and still perform all the automatic functions possible with flash photography. The adapter has a locking pin to prevent it from dropping off the flash. Usable Flashes: Speedlites 160E, 200E, 300EZ, 420EZ,420EX 430EZ,430EX, 540EZ,480 EG,550EX & 580EX.