Fuel Mixture Formation. Manufacturer: ELRING. Bolt Head-/Nut Design: Female Torx. Axle Drive. Belt Drive. Thread Size 1: M12x1,75x137. Thread Size 2: M12x1,75x177. Once that option is no longer available, we may not be able to cancel anymore, however, and as long as we haven’t processed your order yet, we will do everything we can to stop your order.