The SL Series and TL Series signal lights are often used to signal the door status in buses and trains. Passengers thus know when the door will open or close. The rounded housing design ensures optimal recognition, because the warning signal can be seen from different perspectives. TSL’s signal lights are suitable for the door area on both the interior and exterior of public transport vehicles. Although the door area is one of the most important application areas for the signal lights, depending on the specific product, they can also be used in buildings or industry. The SLE63, for example, can be used in engine rooms or for access control. The SLE150 is also used as a start and stop light or signal and warning light in industrial applications.