Abstract: A grommet includes an umbrella-shaped member that is separate from a grommet body. The umbrella-shaped member has a covering portion that covers an insertion hole of a sound insulator provided on one surface of a vehicle body panel. The covering portion is inclined to increase in diameter toward the sound insulator. The grommet body has an engagement portion that axially locks to a front end of the covering portion, which is the front end of the umbrella-shaped member.

Abstract: An apparatus for igniting a plurality of detonating primers including an oscillator for generating a microwave, a transmitting antenna for radiating the microwave generated by the oscillator toward receiving antennas connected to the detonating primers, and a shield housing provided between the transmitting antenna and the receiving antennas to surround a microwave propagating space. The shield housing is constructed such that the microwave radiated by the transmitting antenna is not leaked out of the shield housing and spurious electromagnetic waves do not intrude into the space within the shield housing. The detonating primers are positively ignited by the electric power radiated from the transmitting antenna and received by the receiving antennas even if the output power of the oscillator is small. The shield housing also serves to confine noise, scattering stones and fumes within the shield housing.