This is a universally compatible filament sensor. 

The filament sensor can be connected to a Bowden tube coming from the filament spool and does have a slot for a possible cable tie for mounting.

Except for the micro switch, no other parts are needed. It is compatible with most microswitches used in older a8 and i3 type printers as limit switches. If the lever of a switch does not fully fit into the dimensions, a simple bend resolves the issue.

The model currently only fits 1.75 mm filament, an upgrade for 2.85 mm filament is coming soon.

This model is the result of years of development (try and error over a week). It has been shown that the model works without any problems when using a layer thickness of 0.2 mm or less and without a support structure.