I can confirm Masterown's answer. You can find additional brackets, for example, under Thule Chariot hub hitch.
The axle of the bike is crucial for choosing the right axle.

yes, it's the 17 model. last year's had grey plastic parts, here they're black.
storage space for 2 coop paper bags.
yes, the holder fits on every bike. please note that every bike needs its own holder. one holder is enclosed.