Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2746497.

This is a remix of Kiolia's strain relief, which I've modified to suit the Anycubic Linear. The original was designed for the XL and wouldn't fit my printer because my extruder stands proud of the top surface of the effector by 2mm, so this remix has a larger 16mm diameter cutout to clear the top of the extruder.

If you want to check compatibility before printing this, the four mount holes for my extruder are spaced at 12mm x 22mm, and I measured the extruder diameter at 15.95mm.

Thanks to Kiolia for the original design!