set2: 1 x Air Bubble Stone + 1 x Aquarium cleaning pumpHose length: approx. 1.6mHose diameter: approx. 1.7cm100% brand new and high quality,Increase oxygen levels, lower CO2 and raise PH.It is an important instrument to successfully keep aquatic fish for the respiration process.Durable, washable and sintered by high temperature.Creates bubbles in the aquarium when connected to an air pump (air pump not included).Creates water currents and dazzling underwater scenes.Color: white/GreyMaterial: Mineral stone + Plastic/plasticItem size: Approx. 40mm x 15mm (D x H)This air stone is suitable for use in 30-60cm aquariums.Suitable for soft hose with inner diameter 4mm.Before use, please immerse it in the water for 15 minutes.If it has no bubbles in one part, please change the pump to higher power.It will not work normally if you connect it to the submersible pump.Package Contents:1 x Air Bubble Stone1 x Aquarium cleaning pumpOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.