This item is meant  for spin cast rod&reels as a attachment to aid in casting. By adding this it will help with getting rid of the possibility of cuts or tangles.  Original is from thingiverse. I have modified it by adding extra walls and changing the infill pattern to rectilinear. and adding slim tree supports to both parts.

*Fitting*

BY softening the PLA with hot water. Running hot water over the flat side to help soften it for molding. Then quickly apply to your rod and mold it to fit the desired area. 

you  then attached the arm/trigger with a piece of wire (preferably stainless steel) bent on each end to where it will not fall out and can still pivot , or with a small bolt with nylon locking nut threw  the holes of each model.

Finally, just zip tie (minimum 1) to the rod and enjoy.Below is a link on how to set it on your pole