If the laser emits in the visible region then the radiation is perceived as a single colour. The wavelength of light is usually measured in nanometres, or one-thousand-millionth of a metre and is abbreviated to â. â.
A shower or tub equipped with a showerhead shall have a minimum ceiling height of 6 feet 8 inches (2036 mm) above a minimum area 30 inches (762 mm) by 30 inches (762 mm) at the showerhead. The tub/shower is set in an alcove that has as a partial sloped ceiling.
A good height for the shower head is 6 10, but this is really up to you. As for how deep inside the wall to rough the valve, that is entirely dependent on the individual valve and the thickness of wall covering planned. Most new valves will come with a rough-in plate, or plaster guard.