Designed as feet for Astera tubes to prevent rolling when used on a flat surface.
 
Or rig them somewhere funky with the cross-formation zip tie channels.  The design allows the rigging point to be hidden behind the tube for a clean profile.  Have the ability to lock the angle when using tubes as a ground row.  Uses the included M5 knob to fasten into the receiver at either end of an Astera tube.  There's even a little storage hole for said knob.