Abstract: An operation member containing a transmitter for an immobilizer or receiver for the immobilizer, is indicated to a user so that the user may carefully handle the operation menber. An ignition key (1) has a grip (3) and a key plate (2) protruding from the grip (3). “Immobi” is engraved on the surface of the grip (3) to thereby form a first indication portion (11). “Immobi” is an abbreviation for an English word “immobilize”. Inside the grip (3) is contained a transponder which is an immobilizer transmitter.

Abstract: A container made from a hard synthetic resin is provided on a key body (12). A container half (26) and the other container half (27) of the container (16) are attached to a key body (12) and a transmitting element (18) is secured to the container halves (26) and (27) in a sealed condition. A soft resin outer skin is molded on the outer surfaces of the key body (12) and the resin container (16). Heat and pressure during the molding of the resin outer skin are received by the resin container (16) so that the transmitting element 18 therein is protected therefrom.

Abstract: In a cylinder lock, half tumblers are slidably arranged in pairs in the tumbler inserting holes formed in the key rotor in such a manner that, when the key is not inserted into the lock, the half tumblers are elastically urged in one direction to cause their engaging end portions to engage with the locking engagement grooves formed in the cylinder body to inhibit the rotation of the key rotor. When the key is inserted into the lock, the key engaging portions of the half tumblers engage the key crests to move the half tumblers to disengage their engaging end portions from the locking engagement grooves. When, instead of the key, a picking tool is used to disengage one of each pair of half tumblers from the locking engagement groove to thereby allow the key rotor to turn through a predetermined angle, the other half tumbler is engaged with the locking engagement groove deeper than usual, and the protruded portion of the key rotor covers the key engaging portion, thereby preventing the picking of the lock.