The TK Extended Filler Plugs are designed with built-in labyrinth overflow protection. These threaded extended plugs are made of thermoplastic materials (polyamide 66) and can operate with a maximum temperature of 100°C. They function by minimizing the possibility of oil overflow coming from the breather hole. This overflow usually takes place when strong oil movement happens while the labyrinth is integrated at the top of the plug, therefore decreasing the space needed at the bottom surface. The breather hole has a diameter of 2.5 mm.