I like to design even the smallest thing during evenings for quick 3D printing. If you use proper ACID MTB fenders during muddy season, they have hole for rear light wire. This is a snap fit plug with arrow. Point it anywhere. →
Print it upside down, 0.2mm layers, no brim or supports. Change the color after 3 layers to highlight the arrow.
The author marked this model as their own original creation.