at point 40 in the sealing rim region is considerably greater than the wall thickness at point 42 in the adjoining wall region said wall thickness variation can easily be produced by simply varying the draft angle from that which would ordinarily be used when molding plastic articles in order to withdraw the molded article from the mold as can be further noted from said drawing the front sealing surface 25 of said sealing rim 22 is provided with depressions 44 and 46 which accommodate melted plastic flash when a plastic lens member is ultrasonically or vibrationally welded to the reflector member at said surface both longitudinally extending depressions in the front sealing surface of the sealing rim cooperate in precluding the plastic wall flash from either becoming deposited on the inner reflecting surface 48 of the reflector member or forming a deposit on the side edge 50 of the sealing rim 22 which can impair subsequent mounting of the completely assembled par lamp referring to fig3 there is shown the unassembled parts of a prefocused mount and reflector lamp construction of the present invention accordingly said mount construction 60 comprises an assembly of a plastic inner container member 62 which.