Anonymous,
WiFi protocols (IEEE 802.11--) were written only with protocols in mind. As long as your device (IMac in this case) supports 802.11a/b/g/n (pick a letter), then you'll be able to connect.
My personal experience with 802.11 varies widely depending on the construction materials through which the signal must pass. My house has an aluminum-backed polystyrene moisture barrier. Signals do not pass through this material easily. The double-paned windows, however, allow nearly free passage of signals. So, if I am outdoors with my device (whether it's my netbook, my laptop, my tablet, or my smartphone) then I have to be near a (closed) window to get reception. An acquaintance ran a CAT6 wire from his home to his 'very' detached garage (less than 300 feet) and terminated with a range extender. He tells me it works flawlessly. His two-story house is another matter entirely. His primary router is in his cellar, but he had to add an extender on the second floor due, in part, to two floors' worth of wood, floor covering, electrical wiring, copper water piping, and the like.

Belkin N300 Wireless Range Extender should be compatible with ANY primary router. Just keep in mind that if the base (primary) router supports 802.11a/b/g/n/AC, then this product will NOT extend the range of the 802.11AC protocol, but only the 802.11a/b/g/n protocols.