Description: Easy to install, just attached to an air pump. Low pressure is usable, suitable for any air pump. This bubbler does put out very fine bubbles. Made of high-quality materials, non-toxic, safe and durable for use. Good for plants, Co2 is the Key point for a healthy planted aquarium. Specification: Material: Glass + Ceramic + Plastic T23 Size: 15cm/ 5.91inch, Disc Diameter: 2.3cm/ 0.91inch, Disc Part Height: 4cm/ 1.57inch;(approx.) T35 Size: 7cm/ 2.76inch, Disc Diameter: 3.5cm/ 1.38inch, Disc Part Height: 2.5cm/ 0.98inch;(approx.) T60 Size: 7cm/ 2.76inch, Disc Diameter: 6cm/ 2.36inch, Disc Part Height: 2.8cm/ 1.1inch;(approx.) CT100 Size: 7cm/ 2.76inch, Disc Diameter: 6cm/ 2.36inch, Disc Part Height: 2.8cm/ 1.1inch;(approx.) Package Includes: T23 Includes: 1 Piece Air Diffuser T35 Includes: 1 Piece Air Diffuser, 1 Piece Disc, 1 Piece Accessory T60 Includes: 1 Piece Air Diffuser, 1 Piece Disc, 1 Piece Accessory CT100 Includes: 1 Piece Air Diffuser, 1 Piece Disc, 1 Piece Accessory Note: Since the size above is measured by hand, the size of the actual item could be slightly different from the the size above. Due to the lighting effects, monitor settings,etc.There could be some slight difference in the color tone of the pictures and the actual item.