Distance I've tested even in the house, and by 3 rooms. Doors by (approximately 8m).
Works.
After yes the IR sensor at the front of the A7 handle it with surprise that the FB works from behind.
Riddle. In the space of the infrared ray is likely to be reflected from the wall.
DC tested outdoors, haaa, now one has to at least trigger the FB side.
Nevertheless, I am for the price more than satisfied, since my release with the app and smartphone like, but on the fast but often is too expensive.
Absolute buy recommendation.