Service Manuals On Ebay/CD

Anyone buy one of these? Is it an authentic manual or just a generic repair manual?

I have just recently rec'd one of these (my thanks to another member on BuickForums.com). They do appear to be very comprehensive and complete. The one I have covers all years of the RDV. All pages are in PDF format and broken down in several catogories. The entire CD is about 784MB's so I haven't looked through the entire manual but what I have seen is good so far.So going forward I should be able to look up various repairs for RDV owners.