This three-piece track will allow 2.5 mm thick plastic stripping to be pressed into the groove. It helps prevent mounted lights from blinding you while working if they are not very directional. The plastic shown in the image is 2.5 mm thick and 80 mm tall although it should be compliant with variable height stripping. Layer heights of 0.2 with a 0.4 nozzle work well for parameters. It can be scaled up or down to optimize the fit of your material.
The author hasn't provided the model origin yet.