About This Package Includes: 12 pcs of pre-filter sponge (Note: the hole doesn't go all the way through the sponge) Single Hole Sponge: 5.91 x 2.56 inches/ 15 x 6.5 cm (L x H), the inside hole diameter is 2 cm/ 0.8''; For a snug fit, check the size you need carefully before placing an order（ Need to transport, the product is vacuum packed, after receiving it, let it sit for a while to fluff up, it will soon return to its natural volume） Mechanical Filtration: the Replacement Foam Prefilters Fits inside your Pre Filter or water garden pump pre-filter to help reduce pump clogging Easy Replacement: simply replace the sponge with a new one; An essential replacement foam for the water inlet cover of a pre-filter; Ideal for aquariums High Density Sponge: highly porous fine sponge, preventing small or weaker inhabitants from being drawn into the filter, provides lots of surface area for growth and breeding of helpful little creatures, enhances biological filtration and increases the dissolved oxygen level in the aquarium
