20 and 22 shown abstractly here the housing 12 contains a long flat keyhole 24 the keyhole is made long to frustrate efforts to pick the locking mechanism of the tag and to orient any implements inserted other than a key away from the dog 34 that locks the tag the keyhole 24 is in open communication with a key rotation chamber 26 which is in open communication with a slot 28 the slot 28 is in open communication with a bore 30 through which passes in close fitting but movable relationship the long leg 32 of a u shaped hardened bar preferably made from case hardened steel the lower end of the bar 39 s long leg 32 reaches down to and is designed to traverse the length of the slot 28 although in fig1 it is shown at the upper end thereof the lower end of the bar 39 s long leg 32 is formed into a hinged dog 34 the dog 34 is of slightly greatly length than the width of the slot 28 and is oriented in an upward direction it is formed so it is urged to seek a position normal or perpendicular to leg 32 the result is that the dog 34 will jam in slot 28 when upward movement is attempted unless the dog 34 is held upward by a key the cross leg 36 of the.