Bio Media made of Class C plastic is a perfect choice for sump owners who are looking for material that allows easy passage of water. These bio mesh balls have a large surface area for beneficial bacteria to live. Specifications: - Size of filter media bag: 8 " x 5.5 ". - Diameter of bio ball: 1". Includes: - Each bag contains 50 pieces. Caution: * Remove cloth bag with rings inside from the plastic outside packaging. * Wash bags thoroughly prior to putting bio balls into any aquarium system. Shipping Weight: 6 lbs. Handling Time: 1 day