This is a pair of brackets to attach my Altec Lansing VS2421 speakers and my QNIX QX2710 AC Adapters directly to my articulating monitor arms. They're simple S-shaped brackets that are held in place by gravity. Each pair of brackets requires a single M3 screw to attach to the speaker's keyhole slot. These brackets are pretty specific to my hardware, but the OpenSCAD source should be easy enough to modify for other purposes.