produced efficiently and economically in large numbers in fig4 the fastener 10 of the present invention is shown in the molded configuration before a frangible connection 90 between the plunger 60 and the second locking element 40 has been severed the frangible connection 90 is illustrated in greater detail in fig5 which illustrates the same molded configuration as fig4 except turned 90 u00b0 thus in the as molded condition the fastener is a one piece item in fig1 the fastener 10 is shown in a shipped condition prior to actuation of the plunger in this condition the fastener is a one piece item consisting of two individual preassembled pieces which minimizes inventory shipping and installation costs in this configuration the tabs 32 are normal to the spacer 20 thus the first locking element 30 may be placed into the aperture 18 of the chassis 14 the chamfered lower portions 35 of the tabs 32 permit easy insertion of the first locking element 30 along a vertical axis into the aperture 18 this is important because a straight in insertion is desirable if the fastener is to be automatically installed by a machine to the chassis or a circuit board in fig2 the fastener 10 is shown in the partially locked position wherein the first locking element 30 is operative to maintain the fastener 10 affixed to the chassis 14 in this configuration the plunger 60 has been fully extended into the channel 22 such that the lower head 74 is disposed below the protrusions 39 as the lower head 74 moves into the position below the protrusions 39 the tabs 32 will.