Filters out fine particles. Provides crystal clear water. Set includes 4 polyester pads. Variety of types available. Filtering out fine particles and contaminants, the Fluval Plus Polyester Pads - 4 Pack is made for use with the Fluval 2 Plus Underwater Filter. Coming in a variety of types to fit your needs, these pads will keep your water crystal clear to keep your aquatic pals happy and healthy. 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.