Sorry binned it. Useless no difference in water use. Found a cheap head on Fleabay from China. It has lots of minute holes which is great in soft water areas as it won't clog up. Noticed quite good water economy with it. Took a while to arrive as well!
Bought one to replace the standard one they work by sucking in air and mixing it in the water to make it feel like you're getting a good shower with less water. It's great at home with a mains pressure shower but in the m/h no different to an ordinary shower head and the valve sold separately to switch the flow on and off without altering the mixer was too stiff to use.
Better off with an ordinary shower head in a pattern you like but I keep meaning to get a trigger one to make it easier to use.