I recently nearly lost a bike off the car roof when an old rack failed on the motorway so I decided to splash out and bought the X2 pack of this item from Sandicliffe Shop via Amazon.
Like other Thule products, this is top quality equipment and once installed on roof bars, fitting the bikes is a doddle. The rack is adjustable to fit a wide range of bike sizes.
Others have commented on the packaging and the rack is in a strong cardboard box, probably more sutable for sale in a shop than mail order, but it's hard to imagine a vendor unpacking the box and repacking it with bubble wrap or something similar. The keys are in a little slot on the rack, but the box has push-out holes to form handles and the loss of keys another reviewer experienced is a problem waiting to happen. Sandicliffe Shop did wrap mine in strong polythene, making it much less likely and mine arrived quickily and in good condition.
The instructions are the usual Thule diagrams which you either understand or you don't. Happily for those of us who don't, there are videos on youtube showing how the job is done. It's fiddly but not difficult, once you know how.
Other reviewers have mentioned the locks which are the standard Thule type. I think they probably deter people from stealing roof bars simply because wrecking them defeats the point of stealing them. Bearing in mind that even bike locks costing as much as this rack are regularly defeated by experienced thieves, expecting Thule cylinder locks to keep a bike safe is probably unrealistic.
Otherwise the product description on Amazon is clear and accurate so I've not commented on those features.