Metal filter tube are great for aquarium tank, to promote gas exchange and increase dissolved oxygen levels. Great for tropical farms, koi ponds, waste water systems, cooling towers, and other commercial and industrial systems.For use with wet/dry filters (here is not included), to improve biological filtration. Description: Brand new & nice quality An attractive way to make your aquarium shrimp safe Tiny animals like most freshwater shrimp, invertebrates, as well as small and fry are at risk of being sucked into the large slots on most standard intake strainers When cleaning is required, simply brush any accumulated debris off of the filter guard with your hand or a soft brush of some sort like a tooth brush Inner Diamater: Approx. 16mm / 0.63 inch  Whole Size (Dia. x H): Approx. 2.5 x 7cm / 0.98 x 2.75 inch Note: Stainless Steel Filter Guards fit over the filter's intake pipe, not over the strainer. If your filter has an integrated strainer, these Filter Guards will not work without modification. Package includes: 1x Filter Guard