The SRT light tunnel’s main role is the same as the SLT light tunnel’s supplying the interior with the proper amount of natural light. The SRT light tunnel has a rigid light transmitting tube, made of aluminium and covered on its surface with a silver based and light reflective (in 98%) layer. The inside of the tube looks like before mirror. This type of light transmitting tube secures that daylight is conveyed in huge quantities inside the interior. The SRT light tunnel can be used in every kind of buildings, but because of its high effectiveness is recommended to be installed in special building where the daylight is transmitted into long distances e.g. 39' (12 m). The SRT light tunnel can be also used at nights thanks to the light installation kit which performs the function of the lamp.