The Double Wave, shown below, comes with built-in brackets for easy mounting to the wall. The shelf is strong enough to support multiple cats. If the shelf is mounted to the side of a window, the centre portion can be out in front of the window for the cats to watch the outside world. It can be ordered in left or right configurations. The price is $225.00.
The Single Wave (below) can also be ordered in left or right configuration and the price is $95