The devices can emulate either of two Simply Automated dimmers, the US140T single-channel or US2240 dual channel.

I most often use use the '140; its feature set works nicely for window shades, for instance, so that it receives links to set the dim level == open/closure level. Since there's the WUPB bridge, this means my existing wall switches can send to the shades and don't know any better.

The '140 also works well for motion/occupancy sensors, so that it *sends* links when it senses, to the existing light switches. These have timer links that go off after a short delay, but the occupancies reset the timer each time they sense a person (and occasionally a cat.) Due to the aforementioned feline helpers, the occupancies also have links to disable them, so they're on schedules that turn them on after sunset until we go to bed, and then turn them off at sunrise as they aren't needed when there's natural light.