Abstract: A depth filter formed of a plurality of substantially continuous intertwined filaments including a central support zone formed of support filaments having a first diameter and a filter zone formed of filtration filaments having filaments of a second diameter in which the diameters are different or the filaments are constructed of different materials. The invention also relates to an apparatus and a method for making such a depth filter element.

Abstract: A tester for testing sealed lamps and lamp circuits of vehicles includes an elongate housing. The housing has pointed projections extending from one end wall to be received in a base of a lamp and has blunt projections with recesses in the other end wall to receive the prongs of a plug or pigtail which is normally inserted into the base of a lamp. Each of the ends of a bottom wall of the housing have two ports through which light sources, preferably LEDs, are visible and light when the lamp or circuit is functional. A battery is also carried in the housing for the lamp circuit. In a preferred form, the end walls are slidably held by the housing so as to be removable for replacement purposes and to facilitate manufacture.