The QANVEE QS-100A Bio Sponge Filter is a dual-cylinder aquarium filtration system featuring a unique design with two black sponge filters connected by a green central tube. This elegant and durable filter provides efficient biological and mechanical filtration for aquarium water. Key features: • Dual sponge filter design • Quiet and delicate operation • Reliable and durable construction • Elegant and exquisite appearance • Efficient biological filtration • Easy to install and maintain The filter consists of two vertical cylindrical sponge filters with ribbed surfaces that maximize the filtration area. The green central connecting tube includes an adjustable air system for optimal water flow. The dual-filter design provides redundancy and increased filtering capacity compared to single sponge filters. The unit is particularly suitable for breeding tanks and aquariums with sensitive fish species due to its gentle filtration action.