The invention describes a connection system comprising at least a male connecting element and a female connecting element which can be connected to each other, as well as the male connecting element and the female connecting element. The light collection mask has an opening. Alternatively, a non-resilient lead may be provided with a slotted retainer tube. The plate is placed below the bottom grounded plate. As a result of this, it is possible to improve the fuel consumption of a vehicle when the engine is operated at idle at standstill compared to a case where the engine is operated at idle at the minimum rotation speed Nemin for which the prescribed rotation speed N2 is set regardless of whether or not the vehicle is at a standstill.