End of Filament switch holder, 5 versions

I made this switchholder because i was tired to wait all the time that my spool was out of filament. I guess, like everyone, you try to use all your filament before you change to a new spool. I took a spare endstopswitch and create this bracket for.
The idea is that i mount this bracket roundabout 30cm away of extrudermotor, after the last filament is thru the bracket, the switch close the contact and a buzzer (or so) makes some noise. Depending on your setup you have enough time to activate th