Bought 10, it is not worth more. True, the installation is easy (just plug) but the hard drive is not completely locked in the can, even after screwed. The screw holes are also not very well aligned. It is a useful product that fills his work in point bar so do not expect more. The included cover is too small for it to slide in the housing: it does not seriously.
By adding 1 or 2, you can have a housing that holds just over the road but if, as in my case, your use is occasional, it can be a good plan.