A flash diffuser type for vivitar 285hv?

Hello everyone, and thank you for your time. I have been using my Canon 5D and 35mm f/1.4 L with the Vivitar 285HV as many may already know. So far everything as been strange but a fun adventure, but know i come to another difficult decision, a flash diffuser with more choices to choose then possible! so is this a good choice for a budget sort of do all diffuser? thank you! [8-)]

http://cgi.ebay.com/Flash-Diffuser-VIVITAR-285HV-DF383-DF283-SF4000-/230489064464?pt=Camera_Flash_Accessories&hash= item35aa380410