Easy to print cable puller with magnet slots inside. You can use the pre-configured gcode that has pause in right time, or you can add your own pause. 

I used 3 of 12x1mm magnets inside the slot to have extra strong attraction. 

You can use this as general cable or rope puller depending on your needs. Makes it easier to pull RJ45 cable inside the wall to the upper level or mid roof space. Also useful if you print 2x rope parts so you can pull ropes in tight spaces.