GMak
This product is inferior and does not perform well for long. It also has a problematic hot shoe. -First, the flash has a tiny output compared to the 580EXII. If the 580EXII is GN58, then the NW680 is about GN10. Perhaps this is a defective unit, but if so, then it had poor quality and poor QC. - Next, the 5 pins on the underside of the hot shoe are so hard, that you often cannot remove it from the hot show without using a tool, such as a pocket knife, as they lock themselves in the protruding position so you cant pull the flash out of the hot shoe. - Please note that this does NOT "replace" a Canon 580EXII, as it cannot be used with a remote RF trigger, such as a RadioPopper™. A Canon 580EXII can be placed on an RF receiver mount, and will fire when the controller unit sends a signal to the receiver. This NW680 does not fire and cannot be used. - Ive had my 580EXII for over 9 years and it works like a champ. This NW680 hasnt worked longer than 3 months... - Supporting photos are labeled to show the differences in the flash. - Tech support is via email and clearly their native language is Chinese, not English, and communication is difficult.