This is a replacement window winder knob from a Renault traffic van! i had to design it this way as i found if i simply made a replica the layer adhesion was not strong enough on the small diameter. The "insert" should be printed on it side to give strength along its length! The Thread is M5 and designed at top limit, so should not need any work after printing. I printed mine with an 0.06mm layer at 50mm/min on an Ultimaker 2