These little filter covers are great and just what you are looking for.
Necessary item for small aquarium inhabitants, A must have product for HOB filters
Key feature:
Prevent debris from into the filter barrel and extend the filter material usage life
Prevents small and baby inhabitants from being drawn into filter
Easy to use, sponge cover directly onto the water inlet of your filter
This sponge also provides additional place for the beneficial bacteria to grow
Specifications:
S size: 2.4 x 1.4 inch (H x W)
Inner hole diameter: 0.6 inch
M size: 3.1 x 1.6 inch (H x W)
Inner Hole Diameter: 0.8 inch
Package include:
2pcs x Powkoo Sponge Cover for Filter
1 x Powkoo Retail Package Box