could function if merely being a barrel abutting portion which surrounds part of the barrel 16 and preferably a majority of the barrel 16 therefore the installation of the invention by passing the locking cylinder 24 through the trigger lock body 38 and the inside of the trigger guard 22 also serves to hold the slide 14 in a reward position the trigger lock body 38 and slide retainer 28 are preferably formed rigidly together as a single unitary mass by casting welding bonding or permanently fastening the body 38 and retainer 28 together hence a first distance between the slide stop of the slide retainer and the body 38 or other handgun attachment region is fixed a second distance between the formed tip of the slide 14 when retracted and a portion of the handgun 12 to which the body 38 attaches can match this first distance so that the slide is prevented from advancing the third component of the present invention is the locking cylinder 24 the construction of which is further illustrated in fig7 9 and 10 as previously stated the locking cylinder 24 is made up primarily of the outer and inner lock cylinders 32 and 34 the outer lock cylinder 32 also has in its substantially cylindrical outer surface at least one positioning flat 54 and preferably two which corresponds in shape to a similar hole positioning flat 56 located in the lock cylinder opening 62 on the left and right vertical plates 40 and 41 the purpose of the.