Other important factors are ensuring the hardness and roughness of the shaft are correct. A shaft hardness of HRC 45 is recommended for a rubber sealing lip, with a roughness of Ra 0.4-0.8. A higher shaft hardness of HRC 60 and shaft roughness of Ra 0.1-0.4 is recommended for a PTFE lip.

Halogen lights are in fact the most commonly used headlights on most cars. Their invention dates back to the 1960s which was as a solution towards generating light with limited resources. Just like the incandescent lights, halogens use heated tungsten filament to produce light. The filament is however encased in a bubble of halogen gas unlike the incandescent, as a measure towards improving longevity and performance. These lights are easy to manufacture making the manufacturing process inexpensive. Moreover replacement costs are also very low. Halogen lights can fit most cars of different models as they come in different sizes and shapes. These lights however do not provide the best visibility as the white HID bulbs and LEDs. Quite a large amount of heat is lost while using these headlights and hence wasted energy. Moreover, they are very fragile requiring extra care unlike the LEDs and HID