My partner created this model, I am uploading it with his permission.
One of our smaller fish got caught in the filter suction opening and died in the filter, so R made this cap for the filter to prevent any other small fish from getting sucked in. The openings are square, measuring 2.6mm on the outside of the model and 2.1mm on the inside of the model.
Printed in PLA, currently installed so I have no photos of the finished product.
The author marked this model as their own original creation.