Touch & Tell / Shower Handle

It is a typical headache that the temperature of the water is not always as the icon shows.
People find it hard to tell hot water from the cold only via the icon on the handle, especially for the colour-blind.
In some badly-maintained hotels, the icons might fall off, which makes it harder to distinguish the temperature of the water.
The difference between Touch & Tell and a normal handle is that the pipes open into the grip and two interlayers are fixed inside the handle which allows cold and hot water to flow separately in the grip.