Our 2.5cm thick filter floss provide excellent fish tank filtration for clean water, traps all extra debris. Works great as first layer filtration. You will receive 150cm L x 40cm W x 2.5cm H VACUUMED PACKING : the floss will be pressed in package. After unpacking, it will slowly restore the original thickness always need 1 day . Our bulk classic white filter floss can easily be cut to any size needed and WILL SAVE YOU EVEN MORE MONEY over purchasing ready-made, pre-cut filter media. ENVIRONMENTALLY FRIENDLY - Our aquarium filter media roll is completely safe for all fish and other aquatic life.