Fine-quality impregnated active carbon. Improves the color, clarity, and smell of the water. Removes dyes, discoloration, medications, and noxious odors. Set includes 4 carbon pads. Available in a variety of types. Designed for use with the Fluval 2 Plus Underwater Filter, the Fluval Plus Carbon Pads - 4 Pack comes in a variety of types and is impregnated with active carbon for excellent filtration. The perfect filter medium, these carbon pads filters out harmful liquids, dyes, and medicines while improving the clarity, color, and smell of the water. About Fluval For over 30 years, Fluval has built a global reputation for the innovation and dependability of their aquatic products. Having earned the trust of fish hobbyists with durable and convenient products, Fluval's pioneering spirit has kept them at the forefront through their creativity and technical advancement. Their canister filtration systems provide an efficiency and reliability with an ease of use that can't be beat. Since introducing their first canister filter in 1982, Fluval has developed a wide product range to meet the needs of their trusting customers.