Material: Aquarium intake filter cover made of 304 mesh material; strong and durable, and rubber is ductile. Size: The Large fits for pipes with an outer diameter of about 17 mm, Small fits for most waterfall filters. Please measure the size before purchasing so that you can buy the right product. Easy to Use: The Intake strainer covers mesh is very fine, avoid inhaling small fish, invertebrates, fry and shrimps into the filter, and prevents inhalation of large amounts of debris that can block the filter system. Good Accessories for Aquarium: Metal filter tubes guard cover is perfect for aquarium/fish tanks, facilitating gas exchange and increasing dissolved oxygen. Application: Suitable for tropical fish farms, fish tanks, aquarium, fish ponds, wastewater systems, cooling towers, recycled water filtration, water treatment industry, or other commercial industrial systems. Specification: Material: 304 Mesh Size Chart: Large: Outer Diameter: 3cm/1.18inch, Inner Diameter: 1.6cm/0.63inch, Height: 8.5cm/3.35inch Small: Outer Diameter: 2.5cm/0.98inch, Inner Diameter: 1.2cm/0.47inch, Height: 6.8cm/2.68inch Package Includes: 1 Piece Filter Mesh Guard(2 Pack) Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful online shopping!