I resized the original model from Christoph Meßner to 25,5 x 25,5 mm for a tight fit in a rectangular tube with an inner diameter of 25 x 25 mm. The top of the cap is a little too small, because of the resizing, but I do not care about that!
I printed it in PETG to be UV resistant.
The author remixed this model.
Resized the original model from 40 x 40 mm to 25,5 x 25,5 mm