It is a simple, well designed piece of equipment designed to achieve the maximum spread of light.
With this fitted to your flash you will stand out in any photo shoot situation, it is large.
But don't let this put you off in purchasing this item.
It is a bit fiddly to fit with the Velcro strap, but once secured in place it is no trouble.
I am in a very fortunate position; I'm a photographer for an amateur theatre group.
With this diffuser on the camera and taking stage shots, it can get in the way because of its size.
I find that I get more or less the same results if I tilt the flash head up to almost vertical and just use the built in catch light panel.
But it really comes into its own with portraits.
Gone is the harsh light falling on the subject's face, it gives a softer more natural look with no red eye.
Also I found there is no reflection when the sitter is wearing spectacles.
Just one small tip, nothing to do with the flash set up, but sometimes with portraits or group shots you see their annoying shadow behind them.
I've done this myself on many occasions, to overcome this problem just move the sitter or group further away from the wall, and then you will achieve the desired effect