PYPABL aquarium air pump accessory kit comes as an all-in-one package, including everything you need: 2 pcs 1.5M/4.9ft standard 4mm air tubes—crafted from soft clear plastic for flexibility and durability, and compatible with nearly all air pumps and most fish tanks, 2 check valves that are essential for preventing water backflow and protecting the pump when the air pump is positioned lower than the tank’s water level, 2 2.3cm/0.9in air stones that continuously generate abundant bubbles to effectively oxygenate your aquarium, 2 suction cups that securely fasten the air tubes to the tank, 1 T-connector for converting 2 outlets into 1, and 1 round air filter cotton that filters airborne dust to extend the air pump’s service life. Additionally, regulating valves can be installed on the air tubes for precise air volume adjustment whenever required, further enhancing usability and making this kit a perfect match for your aquarium air pump.