Features: Bubble plate without air pipe, oxygen pump. Need to purchase additional air pipe, oxygen pump connection will bubble. Bubble disk before use to soak in water for more than 20 minutes, and then connect the air pipe, oxygen pump. Bubble disk bubble amount, with the connected oxygen pump gas, oxygen pump, the greater the bubble amount will be more adequate. If the power of the oxygen pump is not enough, the bubble disk will only partially bubble or not bubble at all. The material is sturdy and durable. It can be used for a long for time and has better dissolved oxygen effect. When the bubble burst into the water, the sound is super quiet. Five sizes for you to choose! Specifications: Material: Air Stone Size: A/B/C/D/E A-Approx.60x50mm/2.36x1.97in B-Approx.80x60mm/3.15x2.36in C-Approx.100x60mm/3.94x2.36in D-Approx.120x70mm/4.72x2.76in E-Approx.150x90mm/5.91x3.54in Package Includes: 1x Aquarium Air Stone note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.