Works just as claimed. An incredibly simple idea that uses downforce from the water to push the brush down against walls and floors with little effort on your part. The tail then reverses to make pulling it back effortless. It applies so much force, in fact, that you really have to tighten down your telescoping pole or it'll collapse on you.

Sadly, I just got a Dolphin Dynamic, so I probably won't find much need for my Wall Whale; great product though.