Fish cave (face goes against glass for viewing)

Put the cave open facing the glass to veiw your fish underground! Concept idea was the whole in the top is for fish and shrimp to use to go in&out and have the open mouth of the cave pressed against the glass so you can still have light from above coverage from larger predator fish and still veiw your fish and shrimp. You can also burry it in the sand just make sure to not cover the top entry hole. Resize as needed as this is not a perfect fit for all aquariums or fish.Use PETG for best results