Light Transfer Efficiency (LTE) measures how effectively and consistently daylight is transferred through a TDD’s optical tubing system and into a room for all daylight hours of the year. This factor is closely linked with the specular reflectance associated with a system’s tubing material. The higher the specular reflectance, the more efficient and consistent the transportation of light is. A high LTE typifies a product that limits light loss and, therefore, delivers an even and dependable amount of light to an interior, regardless of season or weather condition.