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.
1 It is difficult to find a pre-made shower cabinet this small. The usual minimum size is 32 x 32.  The minimum height of 80 (6'-8) over the fixture includes the required minimum clear floor space in front of the fixture, which must also have a minimum height of 80 (6'-8). See Guideline 4.