UMU is a laminated glass that contains liquid crystal sheet between 2 pieces of glass. The switchable light control glass UMU is a laminated glass in which specially manufactured liquid crystal sheet is inserted between 2 sheets of glass.

The transparency of glass is controlled by utilizing the properties of liquid crystal whose molecules align with voltage.

The UMU's liquid crystal has a property, which is randomly aligned LC molecules align with voltage. As seen on the diagrams, the light can not pass through at randomly aligned phase while it can easily pass through when LC molecules align. This the secret from clear to translucent phenomenon.