includes locking mechanism 62 assembly 106 includes a stud plate 108 which defines a hole 110 stud 112 defines a post 114 that is mounted within hole 110 of plate 108 in any suitable manner to mount stud 112 to plate 108 the hollow end of the handcuff key receives stud 112 when the key is inserted into opening 98 of lock pivot 92 during the process of locking and unlocking buckle 16 lock pivot 92 defines a hole 100 which receives a pin 102 defined by key return spring 104 and stud plate 108 defines a hole 120 which receives a second pin 118 thus key return spring 104 is mounted between stud plate 108 and lock pivot 92 therefore when lock pivot 92 is rotated by the handcuff key 63 to the unlock position pins 102 and 118 move closer together which causes spring 104 to develop a force that rotates lock pivot 92 back to its locking position when the force exerted by the key on lock pivot 92 is released during removal of the key 63 from buckle 16 a spring plate 116 is located on the upper surface of stud plate 108 plate 116 defines a hole 122 through which spring 104 can rest.