Question about Omni Bounce attachment

Hi all, I noticed in a few threads, people discuss an attachment for the 420EX called omni bounce by Sto Fen. Can someone please explain what this unit is used for. Thanks

I have a Sto Fen omni bounce. It is a platic adaptor that fits over the flash end on a 420EX. It is made of white opaque plastic and it softens the flash - tones down the glare. I paid $19 for it. Before I bought the Sto Fen I made one from a plastic milk carton and was satisfied. Then I decided to go first class and I bought one.

I'm not entirely sure you need it if you use flash exposure compensation to decrease the strength of the flash, but I do use it - matter of fact I usually just leave it on the 420EX.

2Hog