These are post insertion T-Nuts that can be added anywhere along the slot of V-Slot or compatible "20" based extrusions.
They are nice to have on hand because they do not need to be placed in from the ends of the extrusion. They can be easily placed in later in the building process.
Drop in T-Nuts are installed by placing them in the V-Slot and then once the screw is engaged, it will turn them and engage them into the bottom side of the V Track. Once tightened the teeth grab into the anodized coating, to ensure a no-slip connection.
-Fits M3 Screw
-6 x 10.3 x 4.4mm