D5 DZUS panel Line quarter-turn fasteners from Southco, Concordville, Pa., use flare-in studs with all the fastening hardware firmly attached. This eliminates the possibility of dropped or lost parts. The flare cup spring and stud lets the hardware be permanently mounted. When properly installed, the fasteners provide vibration resistance, plus a visual indication that they are securely latched. The devices also prevent anyone from opening the latch without the proper tools. The fasteners can be used on panels with thicknesses varying from 1.27 to 3.28 inches. The fasteners are made of zinc-plated steel.