Optimal Filtration: Our 12 pack of 4 inch filter socks features a honeycomb design, ensuring effective removal of organic matter and debris in aquariums, promoting a healthier aquatic environment. Perfect Size: Each honeycomb filter sock measures approximately 9.8 inches in length and 4 inches in , with a 150- rating perfectly accommodating a variety of filtration systems while ensuring maximum filtration efficiency. Lasting Construction: Made with woven mesh materials, these ring honeycomb filter socks are built to withstand the rigors of aquarium use, preventing damage to aquarium equipment from particles like sand and coral. Versatile Use: These filter socks are essential aquarium filter bags that cater to both saltwater and freshwater fish tanks, making them a versatile addition to your aquarium maintenance toolkit. Color: White Material: Polyester Package Contents: 12 Pack x 4 Inch Filter Sock Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.