The package includes : 1 double filter sponge with 2 containers + 1 bag of ceramic balls + 2 replacement sponges (secretly placed in the 2 containers). The filter should be used with air pump and 4mm air hose. Note: Pump and air hose are not included. Please choose a strong enough air pump according to the size of your aquarium. Easy to Use : Simply use a 4mm air hose, connect one end to the air pump and the other end to the filter. set it above or below the waterline. Removable Thin Sponges : You can easily remove the 2 sponges from the filter to clean or replace it. The 2 sponges are fine 60ppi, which means more surface area for beneficial bacteria to live. Do not use tap water to clean them, just rinse or squeeze sponges using aquarium water. Multi-filtration functions : The aquarium filter combines biofiltration, oxygenation and physical filtration into one. Sponges trap larger debris particles and clean water without catching small fish. Ceramic biofilters help remove harmful