A simple spring bushing for the Anet A8 hotbed springs to prevent warping and bending of the springs. By using the OpenSCAD file it can be adjusted so it should be pretty generic.

The screw is a tight fit but I find that a good thing for it's purpose.

While looking at some other designs and printing them I wasn't quite satisfied so I googled for "spring bushing" and found pictures of similar items and really liked the simplicity and ease of printing so I gave OpenSCAD a try and find the outcome quite nice.